Sammer lens

Abstract

The invention discloses a Chemma lens. The Chemma lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a diaphragm, a sixth lens, a seventh lens, an eighth lens, a ninth lens and a tenth lens which are sequentially arranged from an object plane to an image plane along an optical axis, the first lens is a negative-focal-power lens, the second lens is a positive-focal-power lens, the third lens is a negative-focal-power lens, the fourth lens is a positive-focal-power lens, the fifth lens is a negative-focal-power lens, the sixth lens is a negative-focal-power lens, the seventh lens is a positive-focal-power lens, the eighth lens is a positive-focal-power lens, and the ninth lens is a positive-focal-power lens. The tenth lens is a positive focal power lens; all the lenses are glass spherical lenses. According to the invention, the design of a high-performance Chemma lens which is small in size, low in distortion, large in inclination angle, high in quality and capable of realizing positive imaging and inclined imaging can be realized.

Description

Technical Field

[0001] The invention relates to the technical field of optical lenses, and in particular to a Sham lens. Background Art

[0002] In today's society, machine vision and image processing are developing rapidly, and the application scenarios are expanding day by day, from traditional 2D detection to 3D detection. In three-dimensional space, there are many narrow places, which require more flexible industrial lenses to achieve. Therefore, Sham lenses (also called shift lenses) appear in various industrial inspections. According to Sham's law, when the extended lines of the target plane, the main surface of the lens, and the detector plane intersect in a straight line, the entire tilted target field of view can be clearly imaged.

[0003] Usually, industrial cameras will add protective glass to better protect the chip to achieve protection and dustproof effects, but the introduction of protective glass will produce additional spherical aberration and coma, which is even more difficult for oblique imaging. In addition, in order to correct field curvature and astigmatism to achieve oblique imaging, the existing Sham lens will use a field lens to increase the distance between the positive and negative lenses and slow down the field curvature so that the edge of the larger image plane has sufficient imaging performance, but this design makes the lens bulky and limits the use of scenarios. Summary of the invention

[0004] The present invention provides a Sham lens to realize a high-performance Sham lens design that takes into account small size, low distortion, large tilt angle, high-quality normal imaging and tilt imaging.

[0005] The Sham lens provided by the present invention comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, an aperture, a sixth lens, a seventh lens, an eighth lens, a ninth lens and a tenth lens which are arranged in sequence from the object plane to the image plane along the optical axis;

[0006] The first lens is a negative power lens, the second lens is a positive power lens, the third lens is a negative power lens, the fourth lens is a positive power lens, the fifth lens is a negative power lens, the sixth lens is a negative power lens, the seventh lens is a positive power lens, the eighth lens is a positive power lens, the ninth lens is a positive power lens, and the tenth lens is a positive power lens;

[0007] The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens and the tenth lens are all glass spherical lenses.

[0008] Optionally, the total focal power of the first lens and the second lens is ΦZ1, and the total focal power of the third lens and the fourth lens is ΦZ2, wherein:

[0009] 1.1700≤ΦZ1 / ΦZ2≤1.2700.

[0010] Optionally, the optical power of the fifth lens is ΦL5, and the optical power of the sixth lens is ΦL6, wherein:

[0011] 0.9000≤ΦL5 / ΦL6≤1.1000.

[0012] Optionally, the refractive index of the seventh lens is Nd7, the refractive index of the eighth lens is Nd8, the refractive index of the ninth lens is Nd9, and the refractive index of the tenth lens is Nd10, wherein:

[0013] 1.0900≤MIN(Nd7, Nd8, Nd9) / Nd10≤1.1200.

[0014] Optionally, the Abbe number of the fourth lens is Vd4, and the Abbe number of the fifth lens is Vd5, wherein:

[0015] Vd4 / Vd5≥1.4800.

[0016] Optionally, the maximum aperture of the Sham lens is DM, and the distance from the center of the optical axis of the object side of the first lens to the image plane is TTL, wherein:

[0017] 1.9000≤TTL / DM≤2.1200.

[0018] Optionally, the paraxial magnification of the Sham lens is MAG, where:

[0019] 0.1200≤MAG≤0.1600.

[0020] Optionally, when the Sham lens is in oblique imaging, the sum of the object plane inclination angle and the image plane inclination angle is AOI, where:

[0021] 76.0000≤AOI≤79.0000.

[0022] Optionally, the image height of the Sham lens is IM, and the aperture number of the Sham lens is FN, where:

[0023] 2.9990≤IM / FN≤3.0000.

[0024] Optionally, the Sham lens further includes a first flat glass and a second flat glass, the first flat glass is located in the optical path of the first lens away from the second lens, and the second flat glass is located in the optical path of the tenth lens away from the ninth lens.

[0025] The technical solution of the embodiment of the present invention reasonably allocates the optical power, material and surface shape of each lens in the Sham lens, and sets the first lens to be a negative optical power lens, the second lens to be a positive optical power lens, the third lens to be a negative optical power lens, the fourth lens to be a positive optical power lens, the fifth lens to be a negative optical power lens, the sixth lens to be a negative optical power lens, the seventh lens to be a positive optical power lens, the eighth lens to be a positive optical power lens, the ninth lens to be a positive optical power lens, and the tenth lens to be a positive optical power lens. All ten lenses are glass spherical lenses, thereby realizing a high-performance Sham lens design that can take into account small size, low distortion, large tilt angle, high-quality positive imaging and tilt imaging.

[0026] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 1 is a schematic diagram of the structure of a Sham lens provided in Embodiment 1 of the present invention;

[0029] Figure 2 1 is a schematic diagram of the optical path of the Sham lens provided in the first embodiment of the present invention when forming a positive image;

[0030] Figure 3 1 is a schematic diagram of the optical path of the Sham lens provided in the first embodiment of the present invention during tilted imaging;

[0031] Figure 4 is a light fan diagram of a Sham lens provided in the first embodiment of the present invention;

[0032] Figure 5 is a field curvature distortion curve diagram of the Sham lens provided in the first embodiment of the present invention;

[0033] Figure 6 is a graph showing the positive imaging MTF of the Sham lens provided in the first embodiment of the present invention;

[0034] Figure 7 is an oblique imaging MTF curve diagram of the Sham lens provided in the first embodiment of the present invention;

[0035] Figure 8 1 is a schematic diagram of the structure of a Sham lens provided in Embodiment 2 of the present invention;

[0036] Fig. 9 Schematic diagram of the optical path of the Sham lens provided in the second embodiment of the present invention when forming a positive image;

[0037] Fig.10 Schematic diagram of the optical path of the Sham lens provided in the second embodiment of the present invention during tilted imaging;

[0038] Fig.11 is a light fan diagram of a Sham lens provided in the second embodiment of the present invention;

[0039] Fig.12 is a field curvature distortion curve diagram of the Sham lens provided in the second embodiment of the present invention;

[0040] Fig.13 is a graph showing the positive imaging MTF of the Sham lens provided in the second embodiment of the present invention;

[0041] Fig.14 is an oblique imaging MTF curve diagram of the Sham lens provided in the second embodiment of the present invention;

[0042] Fig.15 1 is a schematic diagram of the structure of a Sham lens provided in Embodiment 3 of the present invention;

[0043] Fig.16 Schematic diagram of the optical path of the Sham lens provided in the third embodiment of the present invention when forming a normal image;

[0044] Fig.17 Schematic diagram of the optical path of the Sham lens provided in the third embodiment of the present invention during tilted imaging;

[0045] Fig.18 is a light fan diagram of a Sham lens provided in Embodiment 3 of the present invention;

[0046] Fig.19 is a field curvature distortion curve diagram of the Sham lens provided in the third embodiment of the present invention;

[0047] Fig. 20 is a graph showing the normal imaging MTF of the Sham lens provided in the third embodiment of the present invention;

[0048] Fig.21 This is a graph of the oblique imaging MTF of the Sham lens provided in the third embodiment of the present invention. DETAILED DESCRIPTION

[0049] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0050] It is obvious to those skilled in the art that various modifications and changes can be made in the present application without departing from the spirit or scope of the present application. Therefore, the present application is intended to cover modifications and changes of the present application that fall within the scope of the corresponding claims (technical solutions for protection) and their equivalents. It should be noted that the implementation methods provided in the embodiments of the present application can be combined with each other without contradiction.

[0051] First of all, it should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Including" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. In addition, the shapes and sizes of the components in the drawings do not reflect the actual proportions, and the purpose is only to illustrate the content of the present invention.

[0052] Embodiment 1

[0053] Figure 1 is a schematic diagram of the structure of a Sham lens provided in the first embodiment of the present invention. Figure 1As shown, the Sham lens provided by the embodiment of the present invention comprises a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, an aperture 106, a sixth lens 107, a seventh lens 108, an eighth lens 109, a ninth lens 110 and a tenth lens 111 which are arranged in sequence along the optical axis from the object plane to the image plane; the first lens 101 is a negative power lens, the second lens 102 is a positive power lens, the third lens 103 is a negative power lens, the fourth lens 104 is a positive power lens, The fifth lens 105 is a negative power lens, the sixth lens 107 is a negative power lens, the seventh lens 108 is a positive power lens, the eighth lens 109 is a positive power lens, the ninth lens 110 is a positive power lens, and the tenth lens 111 is a positive power lens; the first lens 101, the second lens 102, the third lens 103, the fourth lens 104, the fifth lens 105, the sixth lens 107, the seventh lens 108, the eighth lens 109, the ninth lens 110 and the tenth lens 111 are all glass spherical lenses.

[0054] Among them, the focal length is equal to the difference between the convergence of the image-side light beam and the convergence of the object-side light beam, and it characterizes the ability of the optical system to deflect light. The larger the absolute value of the focal length, the stronger the ability to bend light, and the smaller the absolute value of the focal length, the weaker the ability to bend light. When the focal length is a positive number, the refraction of light is convergent; when the focal length is a negative number, the refraction of light is divergent. The focal length can be used to characterize a certain refractive surface of a lens (i.e., a surface of a lens), can be used to characterize a certain lens, and can also be used to characterize a system formed by multiple lenses (i.e., a lens group).

[0055] The glass material can be any type of glass known to those skilled in the art. The thermal expansion coefficient of the lens made of glass is small and the stability is good. When the ambient temperature of the Sham lens changes greatly, it is helpful to keep the focal length of the Sham lens stable. A spherical lens refers to a lens with a constant curvature from the center of the lens to the periphery of the lens.

[0056] The embodiment of the present invention reasonably allocates the optical power, material and surface shape of each lens in the Sham lens, and sets the first lens to be a negative power lens, the second lens to be a positive power lens, the third lens to be a negative power lens, the fourth lens to be a positive power lens, the fifth lens to be a negative power lens, the sixth lens to be a negative power lens, the seventh lens to be a positive power lens, the eighth lens to be a positive power lens, the ninth lens to be a positive power lens, and the tenth lens to be a positive power lens. All the ten lenses are glass spherical lenses, thereby realizing a high-performance Sham lens design that can take into account small size, low distortion, large tilt angle, high-quality positive imaging and tilt imaging.

[0057] like Figure 1As shown, optionally, the surface of the lens adjacent to the object plane is the object surface, and the surface of the lens adjacent to the image plane is the image surface; the object surface of the first lens 101 is convex toward the object plane, and the image surface of the first lens 101 is concave toward the image plane; the object surface of the second lens 102 is convex toward the object plane, and the image surface of the second lens 102 is concave toward the image plane; the object surface of the third lens 103 is concave toward the object plane, and the image surface of the third lens 103 is concave toward the image plane; the object surface of the fourth lens 104 is convex toward the object plane, and the image surface of the fourth lens 104 is concave toward the image plane; the object surface of the fifth lens 105 is convex toward the object plane The image side surface of the fifth lens 105 is concave toward the image plane; the object side surface of the sixth lens 107 is concave toward the object plane, and the image side surface of the sixth lens 107 is convex toward the image plane; the object side surface of the seventh lens 108 is concave toward the object plane, and the image side surface of the seventh lens 108 is convex toward the image plane; the object side surface of the eighth lens 109 is concave toward the object plane, and the image side surface of the eighth lens 109 is convex toward the image plane; the object side surface of the ninth lens 110 is concave toward the object plane, and the image side surface of the ninth lens 110 is convex toward the image plane; the object side surface of the tenth lens 111 is convex toward the object plane, and the image side surface of the tenth lens 111 is convex toward the image plane. By reasonably setting the surface shape of the optical focal length, it is beneficial to the miniaturization design of the Sham lens and reduce the total length of the lens.

[0058] like Figure 1 As shown, optionally, the total focal length of the first lens 101 and the second lens 102 is ΦZ1, and the total focal length of the third lens 103 and the fourth lens 104 is ΦZ2, wherein: 1.1080≤ΦZ1 / ΦZ2≤1.2700.

[0059] Specifically, the first lens 101, the second lens 102, the third lens 103 and the fourth lens 104 are located at the front end of the Sham lens, and the optical powers are arranged in sequence of "negative-positive-negative-positive". When the total optical power of the first lens 101 and the second lens 102 and the total optical power of the third lens 103 and the fourth lens 104 meet the above ranges, multiple turns of peripheral field light can be achieved, the aberration of the edge field of view can be reduced, the field curvature of the peripheral field of view can be effectively corrected, and clear edge resolution can be achieved at different tilt angles.

[0060] like Figure 1 As shown, optionally, the optical power of the fifth lens 105 is ΦL5, and the optical power of the sixth lens 107 is ΦL6, wherein: 0.9000≤ΦL5 / ΦL6≤1.1000.

[0061] Specifically, the fifth lens 105 and the sixth lens 107 are located on both sides of the aperture 106, and have similar optical focal lengths, forming a symmetrical structure relative to the aperture 106. When the optical focal length of the fifth lens 105 and the optical focal length of the sixth lens 107 meet the above conditions, the symmetrical structure and optical focal length can effectively correct system distortion, reduce imaging distortion, and improve detection accuracy.

[0062] like Figure 1 As shown, optionally, the refractive index of the seventh lens 108 is Nd7, the refractive index of the eighth lens 109 is Nd8, the refractive index of the ninth lens 110 is Nd9, and the refractive index of the tenth lens 111 is Nd10, wherein: 1.0900≤MIN(Nd7, Nd8, Nd9) / Nd10≤1.1020.

[0063] Among them, MIN (Nd7, Nd8, Nd9) represents the minimum value of the refractive index Nd7 of the seventh lens 108, the refractive index Nd8 of the eighth lens 109, and the refractive index Nd9 of the ninth lens 110. Specifically, the seventh lens 108 to the tenth lens 111 are located at the rear end of the optical system, and are composed of three high-folding meniscus lenses and a low-folding biconvex lens. Since the use scenario of the Sham lens includes that both the object plane and the image plane are inclined surfaces, more lenses are required to correct the field curvature of the system. The structure and refractive index of this group of lenses can bend the edge light at a shorter distance, which can correct the field curvature more efficiently and reduce the overall volume of the lens.

[0064] like Figure 1 As shown, optionally, the Abbe number of the fourth lens 104 is Vd4, and the Abbe number of the fifth lens 105 is Vd5, wherein: Vd4 / Vd5≥1.4800.

[0065] Specifically, the fourth lens 104 and the fifth lens 105 are close to the aperture 106, and one of the optical focal lengths is positive and the other is negative. By setting the Abbe numbers of the fourth lens 104 and the fifth lens 105 to meet the above conditions and making the difference between the Abbe numbers of the two greatly, the system chromatic aberration can be effectively corrected, the imaging quality can be improved, and the detection effect can be clearer and more accurate.

[0066] like Figure 1 As shown, optionally, the maximum aperture of the Sham lens is DM, and the distance from the center of the optical axis of the object side of the first lens 101 to the image plane is TTL, wherein: 1.9000≤TTL / DM≤2.1020.

[0067] The distance TTL from the center of the optical axis of the object side of the first lens 101 to the image plane can be understood as the total length of the Sham lens. Specifically, while ensuring that the image height remains unchanged, the shorter the total length of the lens, the smaller the maximum aperture, and the smaller the size of the lens. When the total length and the maximum aperture of the lens meet the above conditions, the size can be reduced while achieving a large image height, so that the lens can be more flexibly applied to various environments.

[0068] Optionally, the paraxial magnification of the Sham lens is MAG, where: 0.1020≤MAG≤0.1070, ensuring clear imaging and making it easier to observe details.

[0069] Optionally, when the Sham lens is in oblique imaging, the sum of the object plane inclination angle and the image plane inclination angle is AOI, where: 76.0000≤AOI≤79.0000. Specifically, the Sham lens provided in the embodiment of the present invention can achieve high-quality large-angle imaging, and the object plane inclination angle can reach 62°.

[0070] Optionally, the image height of the Sham lens is IM, and the aperture number of the Sham lens is FN, wherein: 2.9990≤IM / FN≤3.0000.

[0071] Usually, the Sham lens needs a larger depth of field, and the most direct way is to increase the aperture number (i.e., F number) and reduce the aperture of the lens. However, the present invention not only meets the depth of field of a large target surface, but also has a larger aperture, which can obtain more light throughput and avoid the generation of redundant noise by camera exposure, which affects the quality of imaging detection.

[0072] like Figure 1 As shown, optionally, the Sham lens further includes a first flat glass 100 and a second flat glass 112, wherein the first flat glass 100 is located in the optical path of the first lens 101 away from the second lens 102, and the second flat glass 112 is located in the optical path of the tenth lens 111 away from the ninth lens 110. By providing the first flat glass 100 and the second flat glass 112, the internal lens can be protected.

[0073] In summary, for a Sham lens, the greater the image plane tilt angle, the more obvious the field curvature and astigmatism generated, and more lenses are required for correction. Therefore, it is difficult for a Sham lens with a large tilt angle to balance the imaging quality of normal imaging and oblique imaging. Based on the above scheme, the embodiment of the present invention only needs to use 10 glass spherical lenses to achieve a high-performance Sham lens design that takes into account low cost, small size, low distortion, large tilt angle, front and rear flat glass, high-quality normal imaging and oblique imaging. The normal imaging has an MTF of 50pl / mm>0.8MTF, the oblique imaging has an MTF of 50pl / mm>0.6MTF, the object distance is 217mm, the object plane tilt angle can reach 62°, |distortion|<0.5%, the maximum aperture of the lens is ≤φ27.32, the total length of the lens is TTL<55.01mm, and the working band is 390μm~420μm.

[0074] As a feasible implementation, the design values ​​of the optical physical parameters of the Sham lens are described below in conjunction with Table 1.

[0075] Table 1 Design values ​​of Sham lens

[0076]

[0077]

[0078] The surface numbers in Table 1 are numbered according to the order of the surfaces of each lens; the radius of curvature represents the curvature of the lens surface, a positive value represents that the surface is bent toward the object plane, the center of the circle is close to the image plane, and a negative value represents that the surface is bent toward the image plane, the center of the circle is close to the object plane; the thickness represents the central axial distance from the current surface to the next surface; the refractive index represents the ability of the material between the current surface and the next surface to deflect light, and a blank represents that the current position is air, and the refractive index is 1; the Abbe number represents the dispersion characteristics of the material between the current surface and the next surface to the light. The semi-aperture represents half of the aperture size of the current surface.

[0079] For example, Figure 2 1 is a schematic diagram of the optical path of the Sham lens provided in the first embodiment of the present invention when forming a positive image. Figure 3 Schematic diagram of the optical path of the Sham lens provided in the first embodiment of the present invention during tilted imaging. In this embodiment, when the interval between the 25 faces is 10.349 mm, the image plane can be clearly aligned when the object plane is tilted 62°, and the image plane tilt angle is 14.29°. Figure 2 and Figure 3 It can be seen that the light can simultaneously meet the focusing requirements of both normal imaging and oblique imaging, allowing the Sham lens to take into account both normal imaging and large oblique angle imaging.

[0080] Figure 4This is the light fan diagram of the Sham lens provided in Example 1 of the present invention. The light fan diagram is one of the most commonly used evaluation methods in modern optical design. The horizontal axis is the beam diameter, and the vertical axis is the vertical axis aberration. The most ideal curve is a straight line that coincides with the horizontal axis, indicating that all light rays converge at the same point on the image plane, and the corresponding interval on the vertical axis of the curve is the maximum dispersion range of the light beam on the ideal image plane. The light fan diagram can not only reflect the monochromatic aberrations of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. By Figure 4 It can be seen that each wavelength of the system in each field of view is well close to the horizontal axis, indicating that the vertical axis aberration of each wavelength of the system is well corrected. At the same time, there is no obvious dispersion of each wavelength, indicating that the chromatic aberration of the system is also well corrected, thereby ensuring that the optical system can achieve high-resolution imaging requirements.

[0081] Figure 5 : This is a field curvature distortion curve diagram of the Sham lens provided in the first embodiment of the present invention, with the field curvature on the left and the distortion on the right. In the left coordinate system of the figure, the horizontal coordinate represents the magnitude of the field curvature, in units of mm; the vertical coordinate represents the normalized image height, in units of mm; T represents the meridian, S represents the sagittal; Figure 5 It can be seen that the field curvature of the lens provided in this embodiment is effectively controlled, that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small, and the consistency is good; in the coordinate system on the right, the horizontal coordinate represents the size of the distortion, the unit is %; the vertical coordinate represents the normalized image height, no unit; Figure 5 It can be seen that the distortion of the lens provided in this embodiment is well corrected, and the optical distortion is less than ±0.5%.

[0082] Figure 6 : is a graph of the positive image MTF of the Sham lens provided in the first embodiment of the present invention. Figure 6 It can be seen that the image quality of the Sham lens of the present invention at 50 pl / mm from the central field of view to the edge field of view is higher than 0.8 MTF, and the imaging has excellent resolution.

[0083] Figure 7 is an oblique imaging MTF curve diagram of the Sham lens provided in the first embodiment of the present invention, from Figure 7 It can be seen that the image quality of the Sham lens of the present invention at 50 pl / mm from the central field of view to the edge field of view is higher than 0.6 MTF, and the imaging has excellent resolution.

[0084] Embodiment 2

[0085] Figure 8 is a schematic diagram of the structure of a Sham lens provided in the second embodiment of the present invention. Figure 8As shown, the Sham lens provided by the embodiment of the present invention comprises a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, an aperture 106, a sixth lens 107, a seventh lens 108, an eighth lens 109, a ninth lens 110 and a tenth lens 111 which are arranged in sequence along the optical axis from the object plane to the image plane; the first lens 101 is a negative power lens, the second lens 102 is a positive power lens, the third lens 103 is a negative power lens, the fourth lens 104 is a positive power lens, The fifth lens 105 is a negative power lens, the sixth lens 107 is a negative power lens, the seventh lens 108 is a positive power lens, the eighth lens 109 is a positive power lens, the ninth lens 110 is a positive power lens, and the tenth lens 111 is a positive power lens; the first lens 101, the second lens 102, the third lens 103, the fourth lens 104, the fifth lens 105, the sixth lens 107, the seventh lens 108, the eighth lens 109, the ninth lens 110 and the tenth lens 111 are all glass spherical lenses.

[0086] In this embodiment, the optical physical parameter ranges of each lens are the same as those in the first embodiment, and will not be described in detail here.

[0087] Table 2 describes in detail the specific setting parameters of each lens in the Sham lens provided in Example 2 of the present invention in another feasible implementation manner.

[0088] Table 2 Design values ​​of Sham lens

[0089]

[0090]

[0091] The surface numbers in Table 2 are numbered according to the order of the surfaces of each lens; the radius of curvature represents the curvature of the lens surface, a positive value represents that the surface is bent toward the object plane, the center of the circle is close to the image plane, and a negative value represents that the surface is bent toward the image plane, the center of the circle is close to the object plane; the thickness represents the central axial distance from the current surface to the next surface; the refractive index represents the ability of the material between the current surface and the next surface to deflect light, and a blank represents that the current position is air, and the refractive index is 1; the Abbe number represents the dispersion characteristics of the material between the current surface and the next surface to the light. The semi-aperture represents half of the aperture size of the current surface.

[0092] For example, Fig. 9 Schematic diagram of the optical path of the Sham lens provided in the second embodiment of the present invention when forming a positive image. Fig.10 Schematic diagram of the optical path of the Sham lens provided in the second embodiment of the present invention during tilted imaging. In this embodiment, when the interval between the 25 faces is 10.181 mm, the image plane can be clearly aligned when the object plane is tilted 62°, and the image plane tilt angle is 14.08°. Fig. 9 and Fig.10 It can be seen that the light can simultaneously meet the focusing requirements of both normal imaging and oblique imaging, allowing the Sham lens to take into account both normal imaging and large oblique angle imaging.

[0093] Fig.11 This is the light fan diagram of the Sham lens provided in Example 2 of the present invention. The light fan diagram is one of the most commonly used evaluation methods in modern optical design. The horizontal axis is the beam diameter, and the vertical axis is the vertical axis aberration. The most ideal curve is a straight line that coincides with the horizontal axis, indicating that all light rays converge at the same point on the image plane, and the corresponding interval on the vertical axis of the curve is the maximum dispersion range of the light beam on the ideal image plane. The light fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. Fig.11 It can be seen that the system is close to the horizontal axis at each wavelength in each field of view, indicating that the vertical axis aberration of each wavelength of the system is well corrected. At the same time, there is no obvious dispersion of each wavelength, indicating that the chromatic aberration of the system is also well corrected, thus ensuring that the optical system can achieve high-resolution imaging requirements.

[0094] Fig.12 This is a field curvature distortion curve diagram of the Sham lens provided in the second embodiment of the present invention, with field curvature on the left and distortion on the right. In the left coordinate system of the figure, the horizontal coordinate represents the magnitude of field curvature, in units of mm; the vertical coordinate represents the normalized image height, in units of mm; T represents meridian, S represents sagittal; Fig.12 It can be seen that the field curvature of the lens provided in this embodiment is effectively controlled, that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small, and the consistency is good; in the coordinate system on the right, the horizontal coordinate represents the size of the distortion, the unit is %; the vertical coordinate represents the normalized image height, without a unit; Fig.12 It can be seen that the distortion of the lens provided in this embodiment is well corrected, and the optical distortion is less than ±0.5%.

[0095] Fig.13 is a graph of the positive image MTF of the Sham lens provided in the second embodiment of the present invention. Fig.13 It can be seen that the image quality of the Sham lens of the present invention at 50 pl / mm from the central field of view to the edge field of view is higher than 0.8 MTF, and the imaging has excellent resolution.

[0096] Fig.14 is an oblique imaging MTF curve diagram of the Sham lens provided in the second embodiment of the present invention, from Fig.14 It can be seen that the image quality of the Sham lens of the present invention at 50 pl / mm from the central field of view to the edge field of view is higher than 0.6 MTF, and the imaging has excellent resolution.

[0097] Embodiment 3

[0098] Fig.15is a schematic diagram of the structure of a Sham lens provided in Embodiment 3 of the present invention. Fig.15 As shown, the Sham lens provided by the embodiment of the present invention comprises a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, an aperture 106, a sixth lens 107, a seventh lens 108, an eighth lens 109, a ninth lens 110 and a tenth lens 111 which are arranged in sequence along the optical axis from the object plane to the image plane; the first lens 101 is a negative power lens, the second lens 102 is a positive power lens, the third lens 103 is a negative power lens, the fourth lens 104 is a positive power lens, The fifth lens 105 is a negative power lens, the sixth lens 107 is a negative power lens, the seventh lens 108 is a positive power lens, the eighth lens 109 is a positive power lens, the ninth lens 110 is a positive power lens, and the tenth lens 111 is a positive power lens; the first lens 101, the second lens 102, the third lens 103, the fourth lens 104, the fifth lens 105, the sixth lens 107, the seventh lens 108, the eighth lens 109, the ninth lens 110 and the tenth lens 111 are all glass spherical lenses.

[0099] In this embodiment, the ranges of other optical physical parameters of each lens are the same as those in the first embodiment and will not be described in detail herein.

[0100] Table 3 describes in detail the specific setting parameters of each lens in the Sham lens provided in Example 3 of the present invention in another feasible implementation manner.

[0101] Table 3 Design values ​​of Sham lens

[0102]

[0103]

[0104] The surface numbers in Table 3 are numbered according to the order of the surfaces of each lens; the radius of curvature represents the curvature of the lens surface, a positive value represents that the surface is bent toward the object plane, the center of the circle is close to the image plane, and a negative value represents that the surface is bent toward the image plane, the center of the circle is close to the object plane; the thickness represents the central axial distance from the current surface to the next surface; the refractive index represents the ability of the material between the current surface and the next surface to deflect light, and a blank represents that the current position is air, and the refractive index is 1; the Abbe number represents the dispersion characteristics of the material between the current surface and the next surface to the light. The semi-aperture represents half of the aperture size of the current surface.

[0105] For example, Fig.16 Schematic diagram of the optical path of the Sham lens provided in the third embodiment of the present invention when forming a normal image. Fig.17Schematic diagram of the optical path of the Sham lens provided in the third embodiment of the present invention during tilted imaging. In this embodiment, when the interval between the 25 faces is 10.849 mm, the image plane can be clearly aligned when the object plane is tilted 62°, and the image plane tilt angle is 16.52°. Fig.16 and Fig.17 It can be seen that the light can simultaneously meet the focusing requirements of both normal imaging and oblique imaging, allowing the Sham lens to take into account both normal imaging and large oblique angle imaging.

[0106] Fig.18 This is the light fan diagram of the Sham lens provided in Example 3 of the present invention. The light fan diagram is one of the most commonly used evaluation methods in modern optical design. The horizontal axis is the beam diameter, and the vertical axis is the vertical axis aberration. The most ideal curve is a straight line that coincides with the horizontal axis, indicating that all light rays converge at the same point on the image plane, and the corresponding interval on the vertical axis of the curve is the maximum dispersion range of the light beam on the ideal image plane. The light fan diagram can not only reflect the monochromatic aberrations of different wavelengths, but also indicate the size of the vertical axis chromatic aberration. By Fig.18 It can be seen that each wavelength of the system in each field of view is well close to the horizontal axis, indicating that the vertical axis aberration of each wavelength of the system is well corrected. At the same time, there is no obvious dispersion of each wavelength, indicating that the chromatic aberration of the system is also well corrected, thereby ensuring that the optical system can achieve high-resolution imaging requirements.

[0107] Fig.19 This is a field curvature distortion curve diagram of the Sham lens provided in the third embodiment of the present invention, with field curvature on the left and distortion on the right. In the left coordinate system of the figure, the horizontal coordinate represents the magnitude of field curvature, in units of mm; the vertical coordinate represents the normalized image height, in units of mm; T represents meridian, S represents sagittal; Fig.19 It can be seen that the field curvature of the lens provided in this embodiment is effectively controlled, that is, when imaging, the difference between the image quality at the center and the image quality at the periphery is small, and the consistency is good; in the coordinate system on the right, the horizontal coordinate represents the size of the distortion, the unit is %; the vertical coordinate represents the normalized image height, no unit; Fig.19 It can be seen that the distortion of the lens provided in this embodiment is well corrected, and the optical distortion is less than ±0.5%.

[0108] Fig. 20 is a graph of the positive image MTF of the Sham lens provided in the third embodiment of the present invention. Fig. 20 It can be seen that the image quality of the Sham lens of the present invention at 50 pl / mm from the central field of view to the edge field of view is higher than 0.8 MTF, and the imaging has excellent resolution.

[0109] Fig.21 is an oblique imaging MTF curve diagram of the Sham lens provided in the third embodiment of the present invention, from Fig.21It can be seen that the image quality of the Sham lens of the present invention at 50 pl / mm from the central field of view to the edge field of view is higher than 0.6 MTF, and the imaging has excellent resolution.

[0110] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A Sham lens, characterized in that: It includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, an aperture, a sixth lens, a seventh lens, an eighth lens, a ninth lens and a tenth lens which are arranged in sequence from the object plane to the image plane along the optical axis; The first lens is a negative power lens, the second lens is a positive power lens, the third lens is a negative power lens, the fourth lens is a positive power lens, the fifth lens is a negative power lens, the sixth lens is a negative power lens, the seventh lens is a positive power lens, the eighth lens is a positive power lens, the ninth lens is a positive power lens, and the tenth lens is a positive power lens; The first lens, the second lens, the third lens, the fourth lens, the fifth lens, the sixth lens, the seventh lens, the eighth lens, the ninth lens and the tenth lens are all glass spherical lenses.

2. The Sham lens according to claim 1, characterized in that: The total focal power of the first lens and the second lens is ΦZ1, and the total focal power of the third lens and the fourth lens is ΦZ2, wherein: 1.1700≤ΦZ1 / ΦZ2≤1.2700.

3. The Sham lens according to claim 1, characterized in that: The optical power of the fifth lens is ΦL5, and the optical power of the sixth lens is ΦL6, wherein: 0.9000≤ΦL5 / ΦL6≤1.1000.

4. The Sham lens according to claim 1, characterized in that: The refractive index of the seventh lens is Nd7, the refractive index of the eighth lens is Nd8, the refractive index of the ninth lens is Nd9, and the refractive index of the tenth lens is Nd10, wherein: 1.0900≤MIN(Nd7, Nd8, Nd9) / Nd10≤1.1200.

5. The Sham lens according to claim 1, characterized in that: The Abbe number of the fourth lens is Vd4, and the Abbe number of the fifth lens is Vd5, wherein: Vd4 / Vd5≥1.4800.

6. The Sham lens according to claim 1, characterized in that: The maximum aperture of the Sham lens is DM, and the distance from the center of the optical axis of the object side of the first lens to the image plane is TTL, wherein: 1.9000≤TTL / DM≤2.1200.

7. The Sham lens according to claim 1, characterized in that: The paraxial magnification of the Sham lens is MAG, where: 0.1200≤MAG≤0.1600.

8. The Sham lens according to claim 1, characterized in that: When the Sham lens is used for oblique imaging, the sum of the object plane inclination angle and the image plane inclination angle is AOI, where: 76.0000≤AOI≤79.0000.

9. The Sham lens according to claim 1, characterized in that: The image height of the Sham lens is IM, and the aperture number of the Sham lens is FN, wherein: 2.9990≤IM / FN≤3.0000.

10. The Sham lens according to claim 1, characterized in that: The Sham lens further includes a first flat glass and a second flat glass. The first flat glass is located in an optical path of the first lens away from the second lens, and the second flat glass is located in an optical path of the tenth lens away from the ninth lens.

Images