CN216595683U - Large aperture lens - Google Patents

Abstract

The utility model relates to a large-aperture lens which realizes large-aperture imaging through a large-aperture lens. The front barrel lens, the middle barrel and the rear lens barrel are sequentially arranged along the direction of an optical axis, the first lens group and the second lens group are arranged at intervals, and a diaphragm is arranged between the second lens group and the third lens group. The first lens group is provided with a plurality of large-diameter lenses, so that the brightness of an image plane is improved, and light beams received by an object plane can be effectively transmitted into the next lens barrel without large deflection and loss. The diaphragm is arranged in the middle cylinder of the front lens barrel and the rear lens barrel, and can eliminate the influence of intercepting various stray lights so as to improve the picture quality. The large-aperture lens realizes large aperture in a long-focus lens mode, and the imaging of the large aperture can ensure that the brightness of an imaging image surface is uniform and consistent, thereby greatly improving the brightness and the resolution of the image surface.

Description

Large aperture lens

Technical Field

The utility model relates to the field of optical lens equipment, in particular to a large-aperture lens.

Background

The use of machine vision lenses has also reached a very widespread level, mainly for monitoring or measuring purposes, and is most widely used in automated production in particular. The existing machine vision lenses are all of ordinary types, and the aperture is too small, so that the layering sense of an imaging picture is poor and an edge image is dark and fuzzy.

Therefore, it is desirable to provide a large aperture lens to solve the above problems.

SUMMERY OF THE UTILITY MODEL

The utility model relates to a large-aperture lens, which realizes large-aperture imaging through a large-aperture lens, and improves the uniformity of image surface brightness and resolution of the large-aperture lens imaging by adopting the design idea of a telecentric lens, thereby improving the alignment precision. The front barrel lens, the middle barrel and the rear lens barrel are sequentially arranged along the direction of an optical axis, the first lens group and the second lens group are arranged at intervals, and a diaphragm is arranged between the second lens group and the third lens group. The first lens group is provided with a plurality of large-diameter lenses, so that the brightness of an image plane is improved, and light beams received by an object plane can be effectively transmitted into the next lens barrel without large deflection and loss. The diaphragm is arranged in the middle cylinder of the front lens barrel and the rear lens barrel, and can eliminate the influence of intercepting various stray light so as to improve the picture quality. The large-aperture lens realizes large aperture in a long-focus lens mode, and has the advantages of long working distance and enlarged imaging. The imaging of the large aperture can ensure that the brightness of the imaging image surface is uniform and consistent, greatly improve the brightness and the resolution of the image surface, and solve the problems of poor imaging picture layering sense and dark and fuzzy edge images caused by too small aperture in the prior art.

In order to solve the problems, the utility model comprises the following steps: a large aperture lens, comprising:

the lens barrel comprises a front barrel body and a first lens group; the first lens group is arranged in the front barrel and comprises a plurality of lenses which are sequentially arranged along the direction of an optical axis;

the middle barrel comprises a middle barrel body, a second lens group and a diaphragm, and one end of the middle barrel body is fixedly connected with the other end of the front barrel body; the second lens group is arranged in the middle cylinder, and a gap is formed between the second lens group and the first lens group; the diameter of the first lens group is larger than that of the second lens group; the other end of the middle cylinder body is provided with the diaphragm; and (c) a second step of,

the rear lens cone comprises a rear cylinder body and a third lens group; one end of the rear cylinder body is fixedly connected with the other end of the middle cylinder body, the diaphragm is arranged at the joint of the rear cylinder body and the middle cylinder body, and the distance between the diaphragm and the second lens group is different from the distance between the diaphragm and the third lens group.

In the large aperture lens of the utility model, the first lens group includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens. The first lens and the second lens are respectively set as single lenses, and the third lens and the fourth lens, and the fifth lens and the sixth lens are respectively combined and set as close-joint cemented lenses. The combination of a plurality of single lenses and double cemented lenses can effectively correct aberration, and the imaging quality of the large aperture is obviously improved.

Furthermore, the first lens is a biconvex lens, the second lens is a convex-concave lens, the third lens and the fifth lens are both biconvex lenses, the fourth lens is a concave-convex lens, and the sixth lens is a concave-flat lens, so that the uniformity of the image surface brightness and the resolution of the large-aperture lens can be improved, and the alignment precision is improved.

Furthermore, the center thicknesses of the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are different, which is beneficial to improving the imaging quality.

Furthermore, the first lens, the third lens and the fifth lens are made of the same material, so that the cost is saved.

Furthermore, the distances between the adjacent lenses in the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are different, which is beneficial to improving the imaging quality.

Furthermore, the second lens group comprises a seventh lens, and the seventh lens is a cylindrical lens structure, so that optical path compensation can be performed, and a large number of light beams entering from the front end can be effectively absorbed to form a large aperture structure.

Further, the third lens group includes an eighth lens, a ninth lens, a tenth lens, an eleventh lens and a twelfth lens; the eighth lens is a single lens, and the ninth lens and the tenth lens, and the eleventh lens and the twelfth lens are combined to form a cemented lens in close contact with each other. The combination of a plurality of single lenses and double cemented lenses can be used for effectively correcting aberration, and the imaging quality of the large aperture is obviously improved.

Furthermore, the eighth lens and the eleventh lens are concave-convex lenses, the ninth lens is a double-concave lens, and the tenth lens and the twelfth lens are double-convex lenses, so that the uniformity of the image surface brightness and the resolution of the large-aperture lens can be improved, and the alignment precision can be improved.

Furthermore, the center thicknesses of the eighth lens, the ninth lens and the tenth lens are the same, and the center thicknesses of the eighth lens, the eleventh lens and the twelfth lens are different, so that the imaging quality is improved.

Compared with the prior art, the large-aperture lens has the beneficial effects that: the utility model relates to a large-aperture lens, which realizes large-aperture imaging through a large-aperture lens, and adopts the design idea of a telecentric lens to improve the uniformity of image surface brightness and resolution of the large-aperture lens imaging and improve the alignment precision. The front barrel lens, the middle barrel and the rear lens barrel are sequentially arranged along the direction of an optical axis, the first lens group and the second lens group are arranged at intervals, and a diaphragm is arranged between the second lens group and the third lens group. The first lens group is provided with a plurality of large-diameter lenses, so that the brightness of an image plane is improved, and light beams received by an object plane can be effectively transmitted into the next lens barrel without large deflection and loss. The diaphragm is arranged in the middle cylinder of the front lens barrel and the rear lens barrel, and can eliminate the influence of intercepting various stray lights so as to improve the picture quality. The large-aperture lens realizes large aperture in a long-focus lens mode and has the advantages of long working distance and enlarged imaging. The imaging of the large aperture can ensure that the brightness of the imaging image surface is uniform and consistent, greatly improve the brightness and the resolution of the image surface, and solve the problems of poor imaging picture layering sense and dark and fuzzy edge images caused by too small aperture in the prior art.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required in the embodiments are briefly introduced below, and the drawings in the following description are only corresponding drawings of some embodiments of the present invention.

Fig. 1 is a schematic structural diagram of a large aperture lens according to an embodiment of the present invention.

Fig. 2 is a front view of a large aperture lens according to an embodiment of the utility model.

Fig. 3 is a schematic cross-sectional view of fig. 2.

Fig. 4 is an image quality analysis diagram of the large aperture lens according to an embodiment of the utility model.

Fig. 5 is an image plane luminance analysis diagram of the large aperture lens according to an embodiment of the utility model.

In the figure: 10. the lens comprises a large-aperture lens, 20 parts of a front cover, 30 parts of a front lens barrel, 31 parts of a front barrel, 321 parts of a first lens, 322 parts of a second lens, 323 parts of a third lens, 324 parts of a fourth lens, 325 parts of a fifth lens, 326 parts of a sixth lens, 33 parts of a first positioning frame, 40 parts of an intermediate barrel, 421 parts of a seventh lens, 43 parts of a diaphragm, 44 parts of a second positioning frame, 50 parts of a rear lens barrel, 51 parts of a rear barrel, 521 parts of an eighth lens, 522 parts of a ninth lens, 523 parts of a tenth lens, 524 parts of an eleventh lens, 525 parts of a twelfth lens, 53 parts of a third positioning frame, 54 parts of a fourth positioning frame, 55 parts of a fifth positioning frame, 56 parts of a sixth positioning frame and 60 parts of a rear cover.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

The directional terms used in the present invention, such as "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "side", "top" and "bottom", refer to the orientation of the drawings, and are used for illustration and understanding, but not for limiting the present invention.

In the drawings, elements having similar structures are denoted by the same reference numerals.

For most of the existing machine vision lenses, the technical short plate is that the aperture is too small, the imaging picture has no layering sense, the edge image is dark and unclear, and the like, the actual situation of an object cannot be truly reflected, errors are easy to occur only by light supplement and amplification to observe, and particularly errors are difficult to distinguish when the contrast of the object is poor and the ambient light is not ideal. The large aperture lens 10 can use a large aperture to increase the light input of the whole large aperture lens 10, so that the brightness and uniformity of the image plane are improved. The large-aperture lens 10 has an aperture F5.4 which belongs to a large aperture level in a machine vision lens, adopts a design idea of a telecentric lens, selects more than ten single lenses and multiple groups of double-cemented lenses to match, and adopts a design method of diffraction limit to improve the resolution. A branch capable of matching a coaxial light effect is also arranged in the middle of the system to prepare for environmental restriction of higher light matching requirements.

Referring to fig. 1 and 2, in the present embodiment, the large aperture lens 10 includes a front cover 20, a front barrel 30, a middle barrel 40, a rear barrel 50, and a rear cover 60. The front cover 20, the front lens barrel 30, the middle barrel 40, the rear lens barrel 50 and the rear cover 60 are sequentially arranged along the optical axis direction, the front cover 20 is fixedly connected with one end of the front lens barrel 30, the rear cover 60 is fixedly connected with the rear lens barrel 50, and the front cover 20 and the rear cover 60 are both used for fixing lenses in the large aperture lens 10.

Referring to fig. 3, in the present embodiment, the front lens barrel 30 includes a front barrel 31 and a first lens group. One end of the front barrel 31 is fixedly connected with the front cover 20, and the first lens group is arranged in the front barrel 31. The first lens group includes a first lens 321, a second lens 322, a third lens 323, a fourth lens 324, a fifth lens 325 and a sixth lens 326, the six lenses are sequentially arranged along the optical axis direction, and the distances between two adjacent lenses are different, which is beneficial to improving the imaging quality. The aperture of the lens in the front lens barrel 30 is larger than 30mm, and the lens is larger than a common lens so as to be beneficial to increasing the aperture of the light, greatly improve the resolution capability of the lens, clearly monitor the details of an object and meet the fine requirement.

The first mirror 321 is a biconvex lens, the second mirror 322 is a convex-concave lens, the third mirror 323 and the fifth mirror 325 are biconvex lenses, the fourth mirror 324 is a concave-convex lens, and the sixth mirror 326 is a concave-flat lens, so that the uniformity of the image brightness and the resolution of the image formed by the large aperture lens 10 can be improved, and the alignment accuracy can be improved. The first mirror 321 and the second mirror 322 are each a single lens, and the third mirror 323 and the fourth mirror 324, and the fifth mirror 325 and the sixth mirror 326 are each a cemented mirror in close contact with each other. The combination of a plurality of single lenses and double cemented lenses can effectively correct aberration, and the imaging quality of the large aperture is obviously improved. The center thicknesses of the first lens 321, the second lens 322, the third lens 323, the fourth lens 324, the fifth lens 325 and the sixth lens 326 are all different, which is beneficial to improving the imaging quality.

In the present embodiment, each lens element in the first lens element set is specifically described in detail.

One side of the first lens 321 is tightly attached to the end surface of the front cover 20, the other side is connected to one end of the first positioning frame 33 in an abutting manner, and the first positioning frame 33 is fixedly connected to the front barrel 31. The curvature of the front surface of the first lens 321 is 84.66mm, the curvature radius of the back surface is-225.23 mm, the center thickness of the first lens 321 is 6.95mm, the material of the first lens 321 is H-FK61B, and the effective aperture is phi 46 mm.

One side of the second lens 322 is closely attached to the other side of the first positioning frame 33, wherein the distance between the first lens 321 and the second lens 322 is 53.87mm, that is, the length of the first positioning frame 33 along the optical axis direction is 53.87 mm. The radius of curvature of the front surface of the second lens 322 is 77.27mm, the radius of curvature of the back surface is 47.02mm, the center thickness of the second lens 322 is 5.1mm, the material of the second lens 322 is H-F4, and the effective caliber is 34 mm.

The spacing between the third mirror plate 323 and the second mirror plate 322 is 1.07 mm. The radius of curvature of the front surface of the third lens 323 is 77.806mm, the radius of curvature of the back surface is-44.58 mm, the center thickness of the third lens 323 is 6.93mm, the material of the third lens 323 is H-FK61B, and the effective aperture of the third lens 323 is phi 34 mm.

The fourth lens 324 is adhesively bonded to the third lens 323. The radius of curvature of the front surface of the fourth lens 324 is-44.58 mm, the radius of curvature of the back surface is-284.57, the center thickness of the fourth lens 324 is 2.5mm, the material of the fourth lens 324 is H-LAF2, and the effective aperture of the fourth lens 324 is phi 34 mm.

The spacing between the fifth lens 325 and the fourth lens is 0.5 mm. The radius of curvature of the front surface of the fifth lens 325 is 35.72mm, the radius of curvature of the back surface is-59.85 mm, the center thickness of the fifth lens 325 is 7.82mm, the material of the fifth lens 325 is H-FK61B, and the effective aperture of the fifth lens 325 is Φ 30 mm. The first lens 321, the third lens 323, and the fifth lens 325 are made of the same material, so as to save cost.

The sixth lens 326 is adhesively bonded to the fifth lens 325. The radius of curvature of the front surface of the sixth lens 326 is-59.85 mm, the radius of curvature of the back surface is 585.35mm, the center thickness of the sixth lens 326 is 4.73mm, the material of the sixth lens 326 is H-ZPK2A, and the effective caliber of the sixth lens 326 is phi 30 mm.

Referring to fig. 3, in the present embodiment, the middle barrel 40 includes a middle barrel 41, a second lens group and a diaphragm 43, and one end of the middle barrel 41 is fixedly connected to the other end of the front barrel 31. The second lens group is disposed in the middle cylinder 41, and a gap is disposed between the second lens group and the first lens group, and the second positioning frame 44 is disposed at the gap for connecting and fixing the sixth lens 326 and the seventh lens 421 at two sides thereof. The diameter of the first lens group is larger than that of the second lens group. The second lens group includes a seventh lens 421, the seventh lens 421 is a cylindrical lens structure, and the distance between the seventh lens 421 and the sixth lens 326 in the front barrel 30 is 5mm, so that the optical path compensation can be performed, and a large amount of light beams entering from the front end can be effectively absorbed, thereby forming a large aperture structure. The diameter of the seventh lens 421 is 26mm, and the material of the seventh lens 421 is H-K9L. The seventh lens 421 is used to compensate the optical length of the entire macro aperture lens 10.

Referring to fig. 3, in the present embodiment, the rear barrel 450 includes a rear barrel 51 and a third lens group. One end of the rear cylinder 51 is fixedly connected with the other end of the middle cylinder 41, and the diaphragm 43 is arranged at the joint of the rear cylinder 51 and the middle cylinder 41. The distance between the diaphragm 43 and the second lens group is different from the distance between the diaphragm 43 and the third lens group. The distance between the diaphragm 43 and the seventh lens 421 is 3mm, and the distance between the diaphragm 43 and the eighth lens 521 in the rear barrel 50 is 18.2 mm. The aperture of the diaphragm 43 can reach phi 14mm, so that a large number of light beams entering from the front end can be effectively absorbed, and a large aperture structure is formed.

The third lens group includes an eighth lens 521, a ninth lens 522, a tenth lens 523, an eleventh lens 524, and a twelfth lens 525, which are sequentially disposed along the optical axis direction. The eighth mirror 521 is a single lens, and the ninth mirror 522 and the tenth mirror 523, and the eleventh mirror 524 and the twelfth mirror 525 are combined to form a cemented lens in close contact with each other. The combination of a plurality of single lenses and double cemented lenses can effectively correct aberration, and the imaging quality of the large aperture is obviously improved. The eighth lens 521 and the eleventh lens 524 are concave-convex lenses, the ninth lens 522 is a double-concave lens, and the tenth lens 523 and the twelfth lens 525 are double-convex lenses, so that the uniformity of the image brightness and the resolution of the image formed by the large-aperture lens 10 can be improved, and the alignment accuracy can be improved. The center thicknesses of the eighth lens 521, the ninth lens 522 and the tenth lens 523 are the same, and the center thicknesses of the eighth lens 521, the eleventh lens 524 and the twelfth lens 525 are different, so that the imaging quality is improved.

In this embodiment, each lens of the third lens group is specifically described in detail.

The eighth mirror 521 and the diaphragm 43 are connected by a third positioning frame 53, and the length of the third positioning frame 53 in the optical axis direction is 18.2 mm. The curvature of the front surface of the eighth lens 521 is 18.5mm, the curvature radius of the rear surface is 14.9mm, the center thickness of the eighth lens 521 is 5mm, the material of the eighth lens 521 is H-LAK53B, and the effective caliber of the eighth lens 521 is phi 16 mm.

The ninth lens 522 is spaced 8.35mm from the eighth lens 521, and is connected to the middle of the eighth lens by a fourth positioning frame 54. The radius of curvature of the front surface of the ninth lens 522 is-17.09 mm, the radius of curvature of the back surface of the ninth lens 522 is 57.13mm, the center thickness of the ninth lens 522 is 5mm, the material of the ninth lens 522 is H-F4, and the effective caliber of the ninth lens 522 is phi 15 mm.

The tenth lens 523 and the ninth lens 522 are adhesively bonded. The curvature of the front surface of the tenth lens 523 is 57.13mm, the curvature radius of the rear surface of the tenth lens 523 is-80.52 mm, the center thickness of the tenth lens 523 is 5mm, the tenth lens 523 is made of H-ZLAF90, and the effective caliber of the tenth lens 523 is phi 19 mm.

The interval between the eleventh lens 524 and the tenth lens 523 is 6.63mm, and the middle is connected by the fifth positioning frame 55. The curvature of the front surface of the eleventh lens 524 is 116.35mm, the curvature radius of the rear surface of the eleventh lens 524 is 24.03mm, the center thickness of the eleventh lens 524 is 4.3mm, the material of the eleventh lens 524 is H-ZF88, and the effective aperture of the eleventh lens 524 is phi 21.6 mm.

The twelfth lens 525 is glued to the eleventh lens 524. The curvature of the front surface of the twelfth lens 525 is 24.03mm, the curvature radius of the rear surface of the twelfth lens 525 is-181.85 mm, the center thickness of the twelfth lens 525 is 5.85mm, the twelfth lens 525 is made of H-ZLAF90, and the effective caliber of the twelfth lens 525 is phi 21.6 mm. The twelfth lens 525 is connected with the back cover 60 through the sixth positioning frame 56, and the distance between the twelfth lens 525 and the inductor is 21.3 mm.

The large aperture lens 10 realizes a large aperture in a long focal length lens mode, and has the advantages of a long working distance and enlarged imaging. The light entrance aperture of the front lens barrel 50 is large enough to obtain more imaging light beams to enter the system, so as to meet the light requirement of the large aperture on the imaging surface. Up to twelve lenses are adopted, wherein four groups of double-cemented lenses are adopted to eliminate aberration so that the resolution of the whole picture is uniform and consistent, and the brightness of the center and the edge is almost the same. And a design method of a telecentric lens diffraction limit is adopted to improve the quality of an imaging surface of the large-aperture lens 10.

The diaphragm 43 is disposed in the middle barrel 40 of the front barrel 30 and the rear barrel 40, so that the front and rear systems are almost symmetrical in sequence, which is a good structure for correcting aberration of the large aperture lens 10, and the aperture of the diaphragm 43 is large, so that the brightness of the image plane is not affected by the reduction of the brightness of the system. Two groups of the cemented lenses appear in the front lens cone, and the two groups of the cemented lenses can eliminate various aberrations under the condition of the large aperture to meet the imaging requirement. The aperture of each lens in the front lens barrel 30 is almost over phi 30mm, so that the light beam received by the object plane can be effectively transmitted into the next lens barrel without large deflection and loss. The rear lens barrel 50 has five single lenses, and the effective aperture is over 15mm, although the aperture is reduced to different degree compared with the aperture of the front lens barrel 30, in order to eliminate the effect of intercepting various stray light and improve the picture quality. Further, the diaphragm 43 is disposed in the intermediate cylinder 40 of the large aperture lens 10, and the number of the diaphragm 43F can be 5.4 and the long focal length can be 115 mm. The imaging of the large aperture can make the brightness of the imaging image surface uniform. The large aperture can effectively and accurately focus the monitored or measured part clearly, has bright theme and highlights the key point, ensures that the focusing picture is clearer, simultaneously lightens the depth of field, is beneficial to highlighting the picture main body and obtains better vision and precision in application. Meanwhile, the large aperture can effectively improve the light inlet quantity in a dark light environment, and the phenomenon that the picture is dark or the edge of the picture is blackened is avoided, so that the brightness and the resolution of the image surface can be improved.

The structure design is made of metal, the anode is oxidized and blackened to eliminate stray reflection, the rear end of the lens is connected with the camera in a mode of adjusting rear intercept, and the adjustment is convenient, fast and reliable. The structure of the adjustable back intercept can be used for conveniently and quickly replacing the camera or adjusting the back intercept to enable the imaging to be clear.

Referring to fig. 4, various aberrations are corrected using a diffraction limited design method and a complex system using up to twelve lenses with four sets of double cemented and multiple single lenses. Fig. 4 is a graph showing the variation of Modulation Transfer Function (MTF) values with spatial frequency for all fields. The lines in the graph represent the MTF values for different fields of view at different frequencies, and it can be seen that each spatial frequency corresponds to multiple sets of MTF values. Wherein the solid line represents the MFT value of the field of view in the meridional direction; the dashed line indicates the MTF values for the field in the sagittal direction. The lens is a symmetrical structure taking an optical axis as a center, MTF values of all directions of the center of a field of view are the same, and at a position deviated from the center, MTF values of a line along a tangential direction and a line along a radial direction are different. Sagittal direction means the direction in which a line parallel to the diameter lies, and meridional direction means the direction in which a line parallel to the tangent line lies.

As can be seen from fig. 4, when the lens is tested, 5 fields are selected for each group of spatial frequencies, and the total number of the fields is 5 solid lines and 5 dashed lines, and each field corresponds to one solid line and one dashed line, that is, the MTF values corresponding to the sagittal direction and the meridional direction. The angle of the field of view corresponding to the uppermost solid line and the dotted line is the smallest, and the angle of the field of view corresponding to the lowermost solid line and the dotted line is the largest. When the spatial frequency H of each field is 70lp/mm, MTF of all fields is larger than 0.5, the diffraction limit is reached, the image plane vignetting phenomenon is avoided, and the imaging quality is high. In the figure, MTF represents the modulation transfer function in line/mm; h represents the spatial frequency in lp/mm (where lp represents the period).

Referring to fig. 5, a large aperture F5.4 can collect a large amount of light, which not only improves the image quality and the image brightness, but also makes the resolution and brightness of the whole image uniform. Fig. 5 below shows relative illumination for different distances from the center to the edge of the labeled image. With the detection of the center of the marked image towards the edge, the relative illumination E of the whole view field is more than 99.2 percent, so the whole picture has no difference in brightness and uniform brightness, the picture obtains better imaging quality, and the brightness, the resolution and the uniformity of the imaged picture are greatly improved. In the figure, E represents relative illuminance in%; d represents the distance in mm from the center to the edge of the index image.

The technical solution of the large aperture lens 10 is fully adapted to the market requirements and may be implemented in many combinations. For example, the number of lenses selected includes, but is not limited to, those listed in this embodiment; the structure of the lens includes but is not limited to using a single lens, also can adopt a structure with two or more groups of double-cemented lenses or a triple-cemented lens, also can use a plurality of aspheric lenses to reduce the number of the lenses or compress the structure size and the like; the optical structure includes but not limited to the front lens cone 30, the middle cylinder 40 and the rear lens cone 50, and there may be two or more groups; the effective aperture of the lens in the rear lens barrel 50 is not necessarily reduced, and may be similar to that in the front lens barrel 30; the large aperture lens 10 is not necessarily designed to have a long focal length mode, and can be designed to have a large aperture with a medium focal length.

The large aperture can greatly obtain light rays from the surface of the object to image, and the brightness of an image surface is improved. The imaging quality can be favorably improved, the imaging quality is better when the aperture is larger, and the brightness, the resolution and the uniformity of an imaging picture are greatly improved by the design of the diffraction limit and the thinking of a large aperture and a telecentric lens. The design of the lens meets the imaging requirement of a large aperture, and solves the long-standing puzzlement problem.

The large-aperture lens 10 can meet the operation requirements of automatic production on precise parts in various environments, can ensure that the picture obtains better imaging quality, improves the brightness of the picture, improves the brightness uniformity of the picture, has the advantage of higher resolution, and can achieve the level of distinguishing details to be clear. Therefore, a series of problems caused by alignment monitoring of each position in the automatic production and assembly process of the mobile phone can be perfectly solved, and the mobile phone is a very good play of applying the design to production.

In this embodiment, the present invention relates to a large-aperture lens, which implements large-aperture imaging through a large-aperture lens, and adopts a telecentric lens design to improve uniformity of image brightness and resolution of the large-aperture lens, thereby improving alignment accuracy. The front barrel lens, the middle barrel and the rear lens barrel are sequentially arranged along the direction of an optical axis, the first lens group and the second lens group are arranged at intervals, and a diaphragm is arranged between the second lens group and the third lens group. The first lens group is provided with a plurality of large-diameter lenses, so that the brightness of an image plane is improved, and light beams received by an object plane can be effectively transmitted into the next lens barrel without too large deflection and loss. The diaphragm is arranged in the middle cylinder of the front lens barrel and the rear lens barrel, and can eliminate the influence of intercepting various stray lights so as to improve the picture quality. The large-aperture lens realizes large aperture in a long-focus lens mode and has the advantages of long working distance and enlarged imaging. The imaging of the large aperture can ensure that the brightness of the imaging image surface is uniform and consistent, greatly improve the brightness and the resolution of the image surface, and solve the problems of poor imaging picture layering sense and dark and fuzzy edge images caused by too small aperture in the prior art.

In summary, although the present invention has been described with reference to the preferred embodiments, the above-described preferred embodiments are not intended to limit the present invention, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, therefore, the scope of the present invention shall be determined by the appended claims.

Claims (10)

1. A large aperture lens, comprising:

the lens barrel comprises a front barrel body and a first lens group; the first lens group is arranged in the front cylinder and comprises a plurality of lenses which are sequentially arranged along the direction of an optical axis;

the middle cylinder comprises a middle cylinder body, a second lens group and a diaphragm, and one end of the middle cylinder body is fixedly connected with the other end of the front cylinder body; the second lens group is arranged in the middle cylinder, and a gap is formed between the second lens group and the first lens group; the diameter of the first lens group is larger than that of the second lens group; the other end of the middle cylinder body is provided with the diaphragm; and the number of the first and second groups,

the rear lens cone comprises a rear cylinder body and a third lens group; one end of the rear barrel is fixedly connected with the other end of the middle barrel, the diaphragm is arranged at the joint of the rear barrel and the middle barrel, and the distance between the diaphragm and the second lens group is different from the distance between the diaphragm and the third lens group.

2. The large aperture lens according to claim 1, wherein the first lens group comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens; the first lens and the second lens are respectively set as a single lens, and the third lens and the fourth lens, and the fifth lens and the sixth lens are respectively combined and set as a close-joint cemented lens.

3. The large aperture lens according to claim 2, wherein the first lens is a biconvex lens, the second lens is a biconvex lens, the third lens and the fifth lens are biconvex lenses, the fourth lens is a concave-convex lens, and the sixth lens is a concave-flat lens.

4. The large aperture lens according to claim 2, wherein the first, second, third, fourth, fifth and sixth lenses have different center thicknesses.

5. The large aperture lens according to claim 2, wherein the first lens, the third lens and the fifth lens are made of the same material.

6. The large aperture lens according to claim 2, wherein the distances between adjacent ones of the first, second, third, fourth, fifth and sixth lenses are different.

7. The large aperture lens according to claim 1, wherein the second group comprises a seventh lens element, and the seventh lens element is configured as a cylindrical lens structure.

8. The large aperture lens according to claim 1, wherein the third lens group comprises an eighth lens, a ninth lens, a tenth lens, an eleventh lens and a twelfth lens; the eighth lens is a single lens, and the ninth lens and the tenth lens, and the eleventh lens and the twelfth lens are combined to form a cemented lens in close contact with each other.

9. The large aperture lens according to claim 8, wherein the eighth lens element and the eleventh lens element are convex-concave lenses, the ninth lens element is a double-concave lens, and the tenth lens element and the twelfth lens element are double-convex lenses.

10. The large aperture lens according to claim 8, wherein the center thicknesses of the eighth lens, the ninth lens and the tenth lens are the same, and the center thicknesses of the eighth lens, the eleventh lens and the twelfth lens are different.

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