A sham lens

Abstract

The application discloses a Schmidt lens, which 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 arranged in sequence along an optical axis from an object plane to an image plane; the first lens is a negative focal length lens, the second lens is a positive focal length lens, the third lens is a negative focal length lens, the fourth lens is a positive focal length lens, the fifth lens is a negative focal length lens, the sixth lens is a negative focal length lens, the seventh lens is a positive focal length lens, the eighth lens is a positive focal length lens, the ninth lens is a positive focal length lens, and the tenth lens is a positive focal length lens; all the lenses are glass spherical lenses. The application can realize high-performance Schmidt lens design with the advantages of small size, low distortion, large tilt angle, high-quality positive imaging and tilt imaging.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical lenses, in particular to a Scheimpflug lens. BACKGROUND

[0002] In today's society, machine vision and image processing are rapidly developing, and the application scenarios are increasingly expanding, from traditional 2D detection to 3D detection. In three-dimensional space, there are many narrow places that require more flexible industrial lenses to achieve, so Scheimpflug lenses (also known as shift lenses) appear in various industrial detections. According to the Scheimpflug law, when the target plane, the lens main plane and the detector plane intersect at a line, the entire tilted target field of view can be clearly imaged.

[0003] Generally, in order to better protect the chip, the industrial camera will increase the protective glass to achieve the protection and dustproof effect, but the intervention of the protective glass produces additional spherical aberration and coma, which is a difficult problem for tilted imaging. In addition, in order to correct the field curvature and image blur to achieve tilted imaging, the existing Scheimpflug lens will use a field lens to increase the spacing between positive and negative lenses to slow down the field curvature, so that the edges of a larger image surface have sufficient imaging performance, but this design leads to a large lens volume and limited use scenarios. SUMMARY

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

[0005] The Scheimpflug lens provided by the present application comprises, in order along the optical axis from the object plane to the image plane, 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;

[0006] 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, the ninth lens is a positive focal power lens, and the tenth lens is a positive focal 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 fifth lens has a refractive power ΦL5, and the sixth lens has a refractive power ΦL6, wherein:

[0011] 0.9000≤ΦL5 / ΦL6≤1.1000.

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

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

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

[0015] Vd4 / Vd5≥1.4800.

[0016] Optionally, the Schmidt lens has a maximum clear aperture DM, and the first lens has a distance from the optical axis center of the object side to the image surface TTL, wherein:

[0017] 1.9000≤TTL / DM≤2.1200.

[0018] Optionally, the Schmidt lens has a paraxial magnification MAG, wherein:

[0019] 0.1200≤MAG≤0.1600.

[0020] Optionally, when the Schmidt lens is in oblique imaging, the sum of the object surface oblique angle and the image surface oblique angle is AOI, wherein:

[0021] 76.0000≤AOI≤79.0000.

[0022] Optionally, the Schmidt lens has an image height IM, and the Schmidt lens has an F-number FN, wherein:

[0023] 2.9990≤IM / FN≤3.0000.

[0024] Optionally, the Schmidt lens further comprises 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 scheme of the embodiment of the present application, by reasonably allocating the refractive power, material and surface shape of each lens in the Sharm lens, setting the first lens as a negative refractive power lens, the second lens as a positive refractive power lens, the third lens as a negative refractive power lens, the fourth lens as a positive refractive power lens, the fifth lens as a negative refractive power lens, the sixth lens as a negative refractive power lens, the seventh lens as a positive refractive power lens, the eighth lens as a positive refractive power lens, the ninth lens as a positive refractive power lens, and the tenth lens as a positive refractive power lens, and setting all the ten lenses as glass spherical lenses, a high-performance Sharm focus lens design that can balance small size, low distortion, large tilt angle, high-quality positive imaging and tilt imaging is realized.

[0026] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present application, nor is it intended to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0028] Figure 1 is a structural schematic diagram of a Sharm lens provided by the first embodiment of the present application;

[0029] Figure 2 is a light path schematic diagram of the Sharm lens provided by the first embodiment of the present application when positive imaging;

[0030] Figure 3 is a light path schematic diagram of the Sharm lens provided by the first embodiment of the present application when tilt imaging;

[0031] Figure 4 is a light ray fan diagram of the Sharm lens provided by the first embodiment of the present application;

[0032] Figure 5 is a field curvature distortion curve diagram of the Sharm lens provided by the first embodiment of the present application;

[0033] Figure 6 is a positive imaging MTF curve diagram of the Sharm lens provided by the first embodiment of the present application;

[0034] Figure 7 is a tilt imaging MTF curve diagram of the Sharm lens provided by the first embodiment of the present application;

[0035] Figure 8 is a structural schematic diagram of a Sharm lens provided by the second embodiment of the present application;

[0036] Figure 9 is a schematic diagram of the optical path of the Schmidt lens provided in Embodiment Two when imaging orthogonally;

[0037] Figure 10 is a schematic diagram of the optical path of the Schmidt lens provided in Embodiment Two when imaging obliquely;

[0038] Figure 11 is a schematic diagram of the ray fan of the Schmidt lens provided in Embodiment Two;

[0039] Figure 12 is a schematic diagram of the field curvature distortion curve of the Schmidt lens provided in Embodiment Two;

[0040] Figure 13 is a schematic diagram of the orthographic imaging MTF curve of the Schmidt lens provided in Embodiment Two;

[0041] Figure 14 is a schematic diagram of the oblique imaging MTF curve of the Schmidt lens provided in Embodiment Two;

[0042] Figure 15 is a schematic diagram of the structure of a Schmidt lens provided in Embodiment Three;

[0043] Figure 16 is a schematic diagram of the optical path of the Schmidt lens provided in Embodiment Three when imaging orthogonally;

[0044] Figure 17 is a schematic diagram of the optical path of the Schmidt lens provided in Embodiment Three when imaging obliquely;

[0045] Figure 18 is a schematic diagram of the ray fan of the Schmidt lens provided in Embodiment Three;

[0046] Figure 19 is a schematic diagram of the field curvature distortion curve of the Schmidt lens provided in Embodiment Three;

[0047] Figure 20 is a schematic diagram of the orthographic imaging MTF curve of the Schmidt lens provided in Embodiment Three;

[0048] Figure 21 is a schematic diagram of the oblique imaging MTF curve of the Schmidt lens provided in Embodiment Three. DETAILED DESCRIPTION

[0049] In the following, the technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application, so that those skilled in the art can better understand the technical solutions of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of the present application.

[0050] It should be noted that various modifications and changes can be made to the present application in light of the above detailed description. Therefore, the present application intends to cover the modifications and changes of this application falling within the scope of the corresponding claims (technical solutions claimed to be protected) and their equivalents. It should be noted that the embodiments provided by the present application can be combined with each other without contradiction, if possible.

[0051] First of all, it should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present application should be understood as the usual meaning understood by those skilled in the art to which the present application belongs. The terms "first", "second" and similar terms used in the present application do not represent any order, number or importance, but are only used to distinguish different components. "Include" and similar terms mean that the elements or objects before the word cover 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 true proportions, but only serve to illustrate the content of the present application.

[0052] Embodiment one

[0053] Figure 1 is a structural schematic diagram of a sham lens provided by the first embodiment of the present application, as shown in Figure 1As shown, the Schmidt lens provided by the embodiment of the present application comprises, in sequence along the optical axis from the object plane to the image plane, a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, a diaphragm 106, a sixth lens 107, a seventh lens 108, an eighth lens 109, a ninth lens 110 and a tenth lens 111; 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] The optical power is equal to the difference between the converging degree of the image-side light beam and the converging degree of the object-side light beam, and it represents the ability of the optical system to deflect light rays. The greater the absolute value of the optical power is, the stronger the ability to bend light rays is, and the smaller the absolute value of the optical power is, the weaker the ability to bend light rays is. When the optical power is positive, the refraction of light rays is converging; when the optical power is negative, the refraction of light rays is diverging. The optical power can be used to represent a certain refractive surface of a lens (i.e., a surface of the lens), a certain lens, or a system (i.e., a lens group) formed by multiple lenses.

[0055] The glass material can be various types of glass known to those skilled in the art. The glass material has a small thermal expansion coefficient and good stability, which is conducive to maintaining the focal length of the Schmidt lens stable when the ambient temperature used by the Schmidt lens changes greatly. The spherical lens represents a lens with constant curvature from the center of the lens to the periphery of the lens.

[0056] The embodiment of the present application rationally allocates the optical power, material and surface shape of each lens in the Schmidt lens, sets the first lens as a negative-power lens, the second lens as a positive-power lens, the third lens as a negative-power lens, the fourth lens as a positive-power lens, the fifth lens as a negative-power lens, the sixth lens as a negative-power lens, the seventh lens as a positive-power lens, the eighth lens as a positive-power lens, the ninth lens as a positive-power lens, and the tenth lens as a positive-power lens, and sets the ten lenses as glass spherical lenses, thereby realizing the design of a high-performance Schmidt lens that can balance small size, low distortion, large tilt angle, high-quality positive imaging and tilt imaging.

[0057] As shown in FIG. 1, the Schmidt lens provided by the embodiment of the present application comprises, in sequence along the optical axis from the object plane to the image plane, a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, a diaphragm 106, a sixth lens 107, a seventh lens 108, an eighth lens 109, a ninth lens 110 and a tenth lens 111. Figure 1As shown, optionally, the surface of the lens adjacent to the object side is the object side surface, and the surface of the lens adjacent to the image side is the image side surface; the object side surface of the first lens 101 protrudes towards the object plane, and the image side surface of the first lens 101 is recessed towards the image plane; the object side surface of the second lens 102 protrudes towards the object plane, and the image side surface of the second lens 102 is recessed towards the image plane; the object side surface of the third lens 103 is recessed towards the object plane, and the image side surface of the third lens 103 is recessed towards the image plane; the object side surface of the fourth lens 104 protrudes towards the object plane, and the image side surface of the fourth lens 104 is recessed towards the image plane; the object side surface of the fifth lens 105 protrudes towards the object plane, and the image side surface of the fifth lens 105 is recessed towards the image plane; the object side surface of the sixth lens 107 is recessed towards the object plane, and the image side surface of the sixth lens 107 protrudes towards the image plane; the object side surface of the seventh lens 108 is recessed towards the object plane, and the image side surface of the seventh lens 108 protrudes towards the image plane; the object side surface of the eighth lens 109 is recessed towards the object plane, and the image side surface of the eighth lens 109 protrudes towards the image plane; the object side surface of the ninth lens 110 is recessed towards the object plane, and the image side surface of the ninth lens 110 protrudes towards the image plane; the object side surface of the tenth lens 111 protrudes towards the object plane, and the image side surface of the tenth lens 111 protrudes towards the image plane. By reasonably setting the surface type of the optical power, the miniaturization design of the Schmidt lens is facilitated, and the total length of the lens is reduced.

[0058] As shown in the figure, Figure 1 Optionally, the total optical power of the first lens 101 and the second lens 102 is ΦZ1, and the total optical power 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 at the front end of the Schmidt lens, and the optical power is arranged in turn as “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 satisfy the above range, the peripheral field of view light can be folded multiple times, the aberration of the edge field of view can be reduced, and the field curvature of the peripheral field of view can be effectively corrected, so that there is a clear edge resolution under different inclination angles.

[0060] As shown in the figure, Figure 1 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 diaphragm 106, and have close optical powers, forming a symmetrical structure relative to the diaphragm 106. When the optical power of the fifth lens 105 and the optical power of the sixth lens 107 satisfy the above conditions, the symmetrical structure and the optical power can effectively correct system distortion, reduce imaging distortion, and improve detection accuracy.

[0062] As shown in Figure 1 , 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] 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 last end of the optical system, and are composed of three high-curved lens and one low-curved lens. Since the use scene of the Schmidt lens includes that the object plane and the image plane are both inclined planes, more lenses are needed to correct the field curvature of the system. The structure and refractive index of this group of lenses can bend the edge light in a shorter distance, which can more efficiently correct the field curvature and reduce the overall size of the lens.

[0064] As shown in Figure 1 , 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 located near the diaphragm 106, and have positive and negative optical powers. By setting the Abbe numbers of the fourth lens 104 and the fifth lens 105 to satisfy the above conditions, the Abbe numbers of the two lenses are greatly different, which can effectively correct the system chromatic aberration, improve the imaging quality, and make the detection effect clearer and more accurate.

[0066] As shown in Figure 1 , optionally, the maximum light aperture of the Schmidt lens is DM, and the distance from the optical axis center 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 on the object side of the first lens 101 to the image plane can be understood as the total length of the Schahm lens. Specifically, while ensuring a constant image height, the shorter the total length of the lens, the smaller the maximum aperture, and the smaller the lens volume. When the total length of the lens and the maximum aperture meet the above conditions, a large image height can be achieved while reducing the volume, making the lens more flexible for use in various environments.

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

[0069] Optionally, when the SAM lens performs oblique imaging, the sum of the object plane tilt angle and the image plane tilt angle is AOI, where: 76.0000≤AOI≤79.0000. Specifically, the SAM lens provided in this embodiment of the invention can achieve high-quality imaging at large tilt angles, with an object plane tilt angle of up to 62°.

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

[0071] Typically, SAM lenses require a greater depth of field, and the most direct method is to increase the aperture number (F-number) and decrease the lens aperture. However, this invention, while satisfying the depth of field requirement for a large target surface, also possesses a large aperture, enabling more light to pass through and avoiding unnecessary noise generated by camera exposure that could affect the quality of image detection.

[0072] like Figure 1 As shown, optionally, the SAM lens also includes a first flat glass 100 and a second flat glass 112. 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 setting the first flat glass 100 and the second flat glass 112, the internal lenses can be protected.

[0073] In summary, for the Sham lens, the greater the image surface inclination angle, the more obvious the field curvature and astigmatism generated, and more lenses are needed for correction, so it is more difficult for the Sham lens with large inclination angle to balance the imaging quality of normal imaging and oblique imaging. Based on the above scheme, the embodiment of the present application only needs to use 10 glass spherical lenses to realize the design of the high-performance Sham lens which takes into account low cost, small size, low distortion, large inclination angle, and high-quality normal imaging and oblique imaging of front and rear flat glass, the 50pl / mm>0.8MTF of normal imaging, the 50pl / mm>0.6MTF of oblique imaging, the object distance of 217mm, the object surface inclination angle of up to 62°, the |distortion|<0.5%, the maximum light aperture of the lens ≤φ27.32, the total length of the lens TTL<55.01mm, and the working waveband of 390μm-420μm.

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

[0075] Table 1: Design values of the Sham lens

[0076]

[0077]

[0078] The surface number in Table 1 is numbered according to the surface order of each lens; the curvature radius represents the bending degree of the lens surface, the positive value represents that the surface is bent to the object side, the center of the circle is close to the image surface, and the negative value represents that the surface is bent to the image side, the center of the circle is close to the object surface; the thickness represents the center axis distance from the current surface to the next surface; the refractive index represents the deflection ability of the material between the current surface and the next surface to the light; the space 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; and the half aperture represents half of the aperture size of the current surface.

[0079] Exemplarily, Figure 2 is a light path schematic diagram of the Sham lens provided by the embodiment one of the present application in normal imaging, Figure 3 is a light path schematic diagram of the Sham lens provided by the embodiment one of the present application in oblique imaging. In the embodiment, when the interval of the 25th surface is 10.349mm, the clear image can be obtained when the object surface is inclined by 62°, and the image surface inclination angle is 14.29°. From Figure 2 and Figure 3 It can be seen that the light can meet the focusing of normal imaging and oblique imaging at the same time, so that the Sham lens can balance normal imaging and large inclination angle imaging.

[0080] Figure 4is the light fan diagram of the Schmidt lens provided by the embodiment one of the present application, and the light fan diagram is one of the most commonly used evaluation methods in modern optical design. The horizontal coordinate is the beam aperture, and the vertical coordinate is the sagittal aberration. The most ideal curve is a straight line coinciding with the horizontal coordinate, which indicates that all light rays converge at the same point on the image plane. The corresponding interval on the vertical coordinate 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 sagittal chromatic aberration. Figure 4 It can be seen that the system is close to the horizontal coordinate at each wavelength under each field of view, which indicates that the sagittal aberration of each wavelength of the system is well corrected. At the same time, there is no obvious dispersion of each wavelength, which indicates that the chromatic aberration of the system is also well corrected, thereby ensuring that the optical system can realize high-resolution imaging requirements.

[0081] Figure 5 is the field curvature distortion curve diagram of the Schmidt lens provided by the embodiment one of the present application, and the left side is the field curvature, and the right side is the distortion. In the left coordinate system, the horizontal coordinate represents the size of the field curvature, and the unit is mm; the vertical coordinate represents the normalized image height, and there is no unit; wherein T represents the meridian, and S represents the sagittal; from Figure 5 It can be seen that the lens provided by the embodiment is effectively controlled in the field curvature, that is, the image quality of the center and the image quality of the periphery are small in the imaging, and the consistency is good; in the right coordinate system, the horizontal coordinate represents the size of the distortion, and the unit is %; the vertical coordinate represents the normalized image height, and there is no unit; from Figure 5 It can be seen that the distortion of the lens provided by the embodiment is well corrected, and the optical distortion is less than ±0.5%.

[0082] Figure 6 is the positive imaging MTF curve diagram of the Schmidt lens provided by the embodiment one of the present application, from Figure 6 It can be seen that the 50pl / mm image quality of the Schmidt lens of the present application from the center field of view to the edge field of view is higher than 0.8MTF, and the imaging has excellent resolving power.

[0083] Figure 7 is the oblique imaging MTF curve diagram of the Schmidt lens provided by the embodiment one of the present application, from Figure 7 It can be seen that the 50pl / mm image quality of the Schmidt lens of the present application from the center field of view to the edge field of view is higher than 0.6MTF, and the imaging has excellent resolving power.

[0084] Embodiment two

[0085] Figure 8 is a structure schematic diagram of a Schmidt lens provided by the embodiment two of the present application, like Figure 8As shown, the Schmidt lens provided by the embodiment of the present application comprises, in sequence along the optical axis from the object plane to the image plane, a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, a diaphragm 106, a sixth lens 107, a seventh lens 108, an eighth lens 109, a ninth lens 110 and a tenth lens 111; the first lens 101 is a negative focal length lens, the second lens 102 is a positive focal length lens, the third lens 103 is a negative focal length lens, the fourth lens 104 is a positive focal length lens, the fifth lens 105 is a negative focal length lens, the sixth lens 107 is a negative focal length lens, the seventh lens 108 is a positive focal length lens, the eighth lens 109 is a positive focal length lens, the ninth lens 110 is a positive focal length lens, and the tenth lens 111 is a positive focal length 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 the embodiment, the optical physical parameter ranges of the lenses are the same as those in the first embodiment, which will not be repeated here.

[0087] Table 2 details the specific setting parameters of the lenses in the Schmidt lens provided by the second embodiment of the present application in another possible implementation manner.

[0088] Table 2 Design values of the Schmidt lens

[0089]

[0090]

[0091] The surface number in Table 2 is numbered according to the surface order of the lenses; the curvature radius represents the bending degree of the lens surface, a positive value represents that the surface is bent toward the object plane side, the center is close to the image plane, and a negative value represents that the surface is bent toward the image plane side, the center is close to the object plane; the thickness represents the center axis distance from the current surface to the next surface; the refractive index represents the deflection ability of the material between the current surface and the next surface to the light; the 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; and the half aperture represents half of the aperture size of the current surface.

[0092] Exemplarily, Figure 9 is a schematic diagram of the optical path of the Schmidt lens provided by the second embodiment of the present application when imaging in the positive direction, Figure 10 is a schematic diagram of the optical path of the Schmidt lens provided by the second embodiment of the present application when imaging in the oblique direction. In the embodiment, when the interval of the 25th surface is 10.181 mm, the object plane can be inclined by 62°, and the image plane is inclined by 14.08°. From the Figure 9 andFigure 10 It can be seen that the light rays can satisfy the focusing of the normal imaging and the oblique imaging at the same time, so that the Schmidt lens can give consideration to the normal imaging and the imaging with large tilt angle.

[0093] Figure 11 is the ray fan diagram of the Schmidt lens provided in Embodiment Two of the present application, and the ray fan diagram is one of the most commonly used evaluation methods in modern optical design. The horizontal coordinate is the beam aperture, and the vertical coordinate is the sagittal aberration. The most ideal curve is a straight line coinciding with the horizontal coordinate, which indicates that all the light rays converge at the same point on the image plane. The corresponding interval on the vertical coordinate of the curve is the maximum dispersion range of the light beam on the ideal image plane. The ray fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the sagittal chromatic aberration. Figure 11 It can be seen that the system is close to the horizontal coordinate at each field of view and each wavelength, which indicates that the sagittal aberration of each wavelength of the system is well corrected. At the same time, there is no obvious dispersion of each wavelength, which indicates that the chromatic aberration of the system is also well corrected, thereby ensuring that the optical system can achieve the requirement of high-resolution imaging

[0094] Figure 12 is the field curvature distortion curve diagram of the Schmidt lens provided in Embodiment Two of the present application, and the left side is the field curvature, and the right side is the distortion. In the left side coordinate system, the horizontal coordinate represents the size of the field curvature, and the unit is mm; the vertical coordinate represents the normalized image height, and there is no unit; wherein T represents the meridian, and S represents the sagittal; from Figure 12 It can be seen that the lens provided in the embodiment is effectively controlled in the field curvature, that is, the image quality of the center and the image quality of the periphery are small in difference, and the consistency is good during imaging; in the right side coordinate system, the horizontal coordinate represents the size of the distortion, and the unit is %; the vertical coordinate represents the normalized image height, and there is no unit; from Figure 12 It can be seen that the distortion of the lens provided in the embodiment is well corrected, and the optical distortion is less than ±0.5%.

[0095] Figure 13 is the normal imaging MTF curve diagram of the Schmidt lens provided in Embodiment Two of the present application, from Figure 13 It can be seen that the image quality of 50pl / mm of the Schmidt lens of the present application from the center field of view to the edge field of view is higher than 0.8MTF, and the imaging has excellent resolving power.

[0096] Figure 14 is the oblique imaging MTF curve diagram of the Schmidt lens provided in Embodiment Two of the present application, from Figure 14 It can be seen that the image quality of 50pl / mm of the Schmidt lens of the present application from the center field of view to the edge field of view is higher than 0.6MTF, and the imaging has excellent resolving power.

[0097] Embodiment Three

[0098] Figure 15is a structural schematic diagram of a Sumar lens provided by Embodiment Three of the present application, as shown in the figure, Figure 15 The Sumar lens provided by the present application comprises, in sequence along the optical axis from the object plane to the image plane, a first lens 101, a second lens 102, a third lens 103, a fourth lens 104, a fifth lens 105, a diaphragm 106, a sixth lens 107, a seventh lens 108, an eighth lens 109, a ninth lens 110, and a tenth lens 111; the first lens 101 is a negative focal length lens, the second lens 102 is a positive focal length lens, the third lens 103 is a negative focal length lens, the fourth lens 104 is a positive focal length lens, the fifth lens 105 is a negative focal length lens, the sixth lens 107 is a negative focal length lens, the seventh lens 108 is a positive focal length lens, the eighth lens 109 is a positive focal length lens, the ninth lens 110 is a positive focal length lens, and the tenth lens 111 is a positive focal length 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 the present embodiment, the other optical physical parameter ranges of the lenses are the same as those in Embodiment One, which will not be described here again.

[0100] Table 3 details the specific setting parameters of the lenses in the Sumar lens provided by Embodiment Three of the present application in another possible implementation manner.

[0101] Table 3 Design values of the Sumar lens

[0102]

[0103]

[0104] The surface number in Table 3 is numbered according to the surface order of the lenses; the curvature radius represents the bending degree of the lens surface, a positive value represents that the surface is bent toward the object plane side, the center is close to the image plane, and a negative value represents that the surface is bent toward the image plane side, the center is close to the object plane; the thickness represents the center axial distance from the current surface to the next surface; the refractive index represents the deflection ability of the material between the current surface and the next surface to the light; the 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; and the half aperture represents half of the aperture size of the current surface.

[0105] An exemplary, Figure 16 is a light path schematic diagram of the Sumar lens provided by Embodiment Three of the present application when positive imaging, Figure 17is a schematic diagram of the optical path of the Schmidt lens provided in Embodiment Three of the present application when imaging obliquely. In this embodiment, when the interval of the 25 facets is 10.849 mm, the object plane can be imaged at an angle of 62°, and the image plane is inclined at an angle of 16.52°. From Figure 16 and Figure 17 It can be seen that the light rays can simultaneously satisfy the focusing of normal imaging and oblique imaging, so that the Schmidt lens can take into account normal imaging and large-angle oblique imaging.

[0106] Figure 18 is a ray fan diagram of the Schmidt lens provided in Embodiment Three of the present application. The ray fan diagram is one of the most commonly used evaluation methods in modern optical design. The horizontal coordinate is the beam aperture, and the vertical coordinate is the sagittal aberration. The most ideal curve is a straight line coinciding with the horizontal coordinate, indicating that all light rays converge to the same point on the image plane. The corresponding interval on the vertical coordinate of the curve is the maximum dispersion range of the light beam on the ideal image plane. The ray fan diagram can not only reflect the monochromatic aberration of different wavelengths, but also indicate the size of the sagittal chromatic aberration. From Figure 18 it can be seen that the system is close to the horizontal coordinate at each field of view and each wavelength, indicating that the sagittal 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] Figure 19 is a field curvature distortion curve diagram of the Schmidt lens provided in Embodiment Three of the present application. The left side is the field curvature, and the right side is the distortion. In the left coordinate system, the horizontal coordinate represents the size of the field curvature, with units of mm; the vertical coordinate represents the normalized image height, without units; where T represents the meridian, and S represents the sagittal. From Figure 19 it can be seen that the lens provided in this embodiment is effectively controlled in the field curvature, that is, when imaging, the difference between the central image quality and the peripheral image quality is small, and the consistency is good; in the right coordinate system, the horizontal coordinate represents the size of the distortion, with units of %; the vertical coordinate represents the normalized image height, without units; from Figure 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] Figure 20 is a normal imaging MTF curve diagram of the Schmidt lens provided in Embodiment Three of the present application. From Figure 20 it can be seen that the 50 pl / mm image quality of the Schmidt lens of the present application from the central field of view to the edge field of view is higher than 0.8 MTF, and the imaging has excellent resolving power.

[0109] Figure 21 is an oblique imaging MTF curve diagram of the Schmidt lens provided in Embodiment Three of the present application. From Figure 21It can be seen that the image quality of the Schmeisser lens of the present application is higher than 0.6 MTF from the center field of view to the edge field of view, and the imaging has excellent resolving power.

[0110] The above detailed description does not constitute a limitation on the protection scope of the present application. 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 replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A Sharm lens characterized in that, 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 arranged in sequence along the optical axis from the object plane to the image plane; The first lens is a negative lens, the second lens is a positive lens, the third lens is a negative lens, the fourth lens is a positive lens, the fifth lens is a negative lens, the sixth lens is a negative lens, the seventh lens is a positive lens, the eighth lens is a positive lens, the ninth lens is a positive lens, and the tenth lens is a positive 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; The surface of the lens adjacent to the object plane side is the object side surface, and the surface of the lens adjacent to the image plane side is the image side surface; the object side surface of the first lens protrudes towards the object plane, and the image side surface of the first lens is recessed towards the image plane; The object side surface of the second lens protrudes towards the object plane, and the image side surface of the second lens is recessed towards the image plane; The object side surface of the third lens is recessed towards the object plane, and the image side surface of the third lens is recessed towards the image plane; The object side surface of the fourth lens protrudes towards the object plane, and the image side surface of the fourth lens is recessed towards the image plane; The object side surface of the fifth lens protrudes towards the object plane, and the image side surface of the fifth lens is recessed towards the image plane; The object side surface of the sixth lens is recessed towards the object plane, and the image side surface of the sixth lens protrudes towards the image plane; The object side surface of the seventh lens is recessed towards the object plane, and the image side surface of the seventh lens protrudes towards the image plane; The object side surface of the eighth lens is recessed towards the object plane, and the image side surface of the eighth lens protrudes towards the image plane; The object side surface of the ninth lens is recessed towards the object plane, and the image side surface of the ninth lens protrudes towards the image plane; The object side surface of the tenth lens protrudes towards the object plane, and the image side surface of the tenth lens protrudes towards the image plane; The total number of lenses with optical power is ten; 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.

2. The Sharm lens of claim 1, wherein, The total optical power of the first lens and the second lens is ΦZ1, and the total optical power of the third lens and the fourth lens is ΦZ2, wherein: 1.1700≤ΦZ1 / ΦZ2≤1.2700.

3. The Sharm lens of claim 1, wherein, 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.

4. The Sharm lens of claim 1, wherein, The Abbe number of the fourth lens is Vd4, and the Abbe number of the fifth lens is Vd5, wherein: Vd4 / Vd5≥1.4800.

5. The Sharm lens of claim 1, wherein, The maximum aperture of the Schmidt lens is DM, and the distance from the optical axis center of the object side surface of the first lens to the image surface is TTL, wherein: 1.9000≤TTL / DM≤2.1200.

6. The Sharm lens of claim 1, wherein, The paraxial magnification of the Schmidt lens is MAG, wherein: 0.1200≤MAG≤0.1600.

7. The Sharm lens of claim 1, wherein, The sum of the object surface tilt angle and the image surface tilt angle of the Schmidt lens when imaging obliquely is AOI, wherein: 76.0000 degrees≤AOI≤79.0000 degrees.

8. The Sharm lens of claim 1, wherein, The image height of the Schmidt lens is IM, and the F-number of the Schmidt lens is FN, wherein: 2.9990≤IM / FN≤3.0000.

9. The Sharm lens of claim 1, wherein, The Schmidt lens further comprises 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.

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