Fisheye large-view-field large-relative-aperture automatic focusing optical lens

Abstract

The invention discloses a fisheye automatic focusing optical lens with a large view field and a large relative aperture. The fisheye automatic focusing optical lens is composed of a negative focal power transmission group G1, a positive focal power transmission group G2, an aperture diaphragm, a negative focal power transmission group G3, a positive focal power transmission group G4 and an image plane which are sequentially arranged from an object space to an image space. 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. The fish-eye large-view-field large-relative-aperture automatic focusing optical lens has the advantages that the working wavelength is a visible light wave band, the object space working distance is 0.2 m to infinity, the view field is 150 degrees, and the relative aperture is 1 / 1.6. The fish-eye large-view-field large-relative-aperture automatic focusing optical lens has the advantages of being large in view field, large in relative aperture, rapid in focusing, good in imaging quality and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of optical lenses, and in particular relates to a fisheye large-field-of-view large-relative-aperture auto-focus optical lens. Background Art

[0002] In recent years, the demand for micro-single cameras in the photography market has been rapidly expanding. With the continuous updating and development of mature high-precision CMOS process device technology, micro-single cameras also have very good high-quality imaging quality. Therefore, their user groups are also increasing, and a variety of different demands have also been generated for various shooting scenes. The focal length range of the original matching lens is still vacant, especially for the autofocus optical lens with large field of view and large relative aperture of fisheye. Not only is the high price leading to low consumer acceptance, but the shooting distance and focusing stroke are both far, resulting in its slow focusing time. Therefore, it is necessary to design a fisheye lens with fast focusing and wide shooting distance range. Summary of the invention

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

[0004] To achieve the above purpose, the technical solution adopted by the present invention is: to provide a fisheye large field of view large relative aperture autofocus optical lens. 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; 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; The aperture stop is located between the transmission group G2 and the transmission group G3.

[0005] According to the fisheye large-field-of-view large-relative-aperture autofocus optical lens of the present invention, a further preferred technical solution is: 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 infinite is (-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 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 in the range of (2.68, 4.08); According to the fisheye large-field-of-view large-relative-aperture autofocus optical lens of 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.

[0006] According to the fisheye large field of view and large relative aperture autofocus optical lens described in 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.

[0007] According to the fisheye large-field-of-view large-relative-aperture autofocus optical lens of the present invention, a further preferred technical solution is: in the transmission group G1, the first positive lens and the third negative lens constitute a double-cemented 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 constitute a double-cemented lens, and the fourth positive lens and the fifth negative lens constitute a double-cemented lens; the transmission group G2 consists of two groups of single lenses.

[0008] Compared with the prior art, the technical solution of the present invention has the following advantages / benefits: 1. The fisheye large-field-of-view large-relative-aperture autofocus optical lens of the present invention has an operating wavelength of 430-656nm, a telephoto distance of infinity, a close-up distance of 0.2m, a field of view of 150 degrees, and a relative aperture of 1 / 1.6, and has the advantages of a large field of view, a large relative aperture, etc.

[0009] 2. The fisheye large-field-of-view 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. The manufacturing cost is low, and its sales price can be significantly reduced. It is easy for consumers to accept and has a good sales prospect.

[0010] 3. The fisheye large-field-of-view large-relative-aperture autofocus optical lens of the present invention has good imaging characteristics, and the whole system has good transfer functions and image points.

[0011] 4. When the object distance of the fisheye large-field-of-view large-relative-aperture auto-focus optical lens of the present invention changes from infinity to close-up distance, the focusing stroke is short, requiring only 0.12 mm, and has the advantage of fast focusing. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 It is a schematic diagram of the structure of the fisheye large-field-of-view large-relative-aperture autofocus optical lens of the present invention.

[0014] Figure 2 It is a modulation transfer function curve of the fisheye large field of view and large relative aperture autofocus optical lens at infinity.

[0015] Figure 3 It is a modulation transfer function curve of the fisheye large field of view and large relative aperture autofocus optical lens at a close shooting distance of the present invention.

[0016] Figure 4 This is a light fan diagram of the fisheye large field of view and large relative aperture autofocus optical lens of the present invention at infinity.

[0017] Figure 5 This is a light fan diagram of the fisheye large-field-of-view, large-relative-aperture autofocus optical lens of the present invention at a close shooting distance.

[0018] Figure 6 This is a point diagram of the fisheye large-field-of-view large-relative-aperture autofocus optical lens of the present invention at infinity.

[0019] Figure 7 This is a point diagram of the fisheye large-field-of-view large-relative-aperture autofocus optical lens of the present invention at a close shooting distance.

[0020] Figure 8 It is the relative illumination curve of the fisheye large-field-of-view large-relative-aperture autofocus optical lens of the present invention.

[0021] The markings in the figure are: 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 DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within 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 the selected embodiments of the present invention.

[0023] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and thus, once an item is defined in one drawing, it may not be further defined or explained in the subsequent drawings.

[0024] Example: Figure 1 This is a schematic diagram of the layout of the fisheye large-field-of-view large-relative-aperture autofocus optical lens of the present invention. From the object side to the image side, 11 optical elements form transmission group G1, transmission group G2, transmission group G3, and transmission group G4.

[0025] 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).

[0026] The transmission group G1 is a transmission group with negative optical power, and 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. Light entering the transmission group G1 is diverged by the transmission group G1 and then enters the transmission group G2.

[0027] The transmission group G2 is a transmission group with positive optical power, and includes a second positive lens 5 made of optical plastic. The light from the transmission group G1 is converged by the transmission group G2 and then enters the transmission group G3.

[0028] The transmission group G3 is a transmission group with negative optical power, and 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 from the transmission group G2 is diverged by the transmission group G3 and then enters the transmission group G4.

[0029] The transmission group G4 is a transmission group with positive power, and includes a fifth positive lens 10 made of crown glass and a sixth positive lens 11 made of crown glass. The light from the transmission group G3 is converged by the transmission group G4 and reaches the image plane.

[0030] The aperture stop is located between the transmission group G2 and the transmission group G3. The transmission group G2 is a moving component, and the transmission groups G1, G3 and G4 are fixed components. The focal length is adjusted by the movement of the transmission group G2.

[0031] The second positive lens is an aspherical lens, and the first positive lens, the third to the sixth positive lenses, and the first to the fifth negative lenses are all spherical lenses. That is, among the 11 lenses as a whole, only the second positive lens is an aspherical lens, and the remaining lenses are spherical. The manufacturing cost is low, and the sales price can be significantly reduced. It is easy for consumers to accept and has a good sales prospect.

[0032] 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.

[0033] The physical parameters of each lens in this embodiment meet the data requirements shown in Table 1: Table 1 Physical parameters of each lens in this embodiment

[0034] The equation for an aspheric surface is as follows:

[0035] The definition of aspherical shape is explained below: y: radial coordinate from the optical axis.

[0036] z: The offset in the direction of the optical axis starting from the intersection point of the aspherical surface and the optical axis.

[0037] r: The radius of curvature of the reference sphere of the aspheric surface.

[0038] k is the cone constant.

[0039] A4, A6, A8, A10, A12, … are 4th, 6th, 8th, 10th, 12th, … aspheric coefficients.

[0040] The surface 8 and the surface 9 of the lens 5 are aspherical surfaces. In Table 2, the 4th, 6th, 8th, 10th, and 12th order aspherical coefficients A4, A6, A8, and A10 and the cone constant k of the aspherical surface are shown together.

[0041] Table 2 Aspheric parameters of this embodiment

[0042] This embodiment is realized by the following technical measures: the working wavelength of the optical lens is 430-656nm, the telephoto distance is infinity, the close-up distance is 0.2m, the field of view is 150 degrees, and the relative aperture is 1 / 1.6. The light is emitted from the object plane and passes through the transmission group G1, the transmission group G2, the transmission group G3, and the transmission group G4 to form an image on the image plane. The present invention has the advantages of large field of view, large relative aperture, fast focusing, good imaging quality, etc.

[0043] Figure 2 , Figure 3 The modulation transfer function curves of the fisheye 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, the ordinate OTF coefficient is the fast Fourier transform modulation transfer function, and the abscissa is the spatial frequency: line pairs per millimeter. It can be seen that the contrast of the fisheye large field of view and large relative aperture autofocus optical lens at infinity and close shooting distances is relatively high, reaching 120lp / mm.

[0044] Figure 4 , Figure 5 The light fan diagram Ray Fan of the fisheye large field of view and large relative aperture autofocus optical lens designed in this embodiment at infinity and close shooting distance is given. In the figure, ex: x component of light aberration, ey: y component of light aberration, px: x entrance pupil coordinate, py: y entrance pupil coordinate. It can be seen that the aberration of the fisheye large field of view and large relative aperture autofocus optical lens at infinity and close shooting distance is small.

[0045] Figure 6 , Figure 7 The spot diagram of the fisheye large field of view and large relative aperture autofocus optical lens designed in this embodiment at infinity and close shooting distance is given, and the unit of the legend in the figure is μm. It can be seen that the image spot of the fisheye large field of view and large relative aperture autofocus optical lens at infinity and close shooting distance is small and has good consistency.

[0046] Figure 8 The relative illumination curve of the fisheye large field of view large relative aperture auto-focus optical lens designed in this embodiment is given. It can be seen that the relative illumination of the fisheye large field of view large relative aperture auto-focus optical lens is better than 0.9.

[0047] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0048] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications 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; 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, 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.

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