High-precision measurement lens and optical system thereof

Abstract

The application relates to the technical field of machine vision lenses, and discloses a high-precision measurement lens and an optical system thereof. The optical system comprises a front group, a light splitting prism and a rear group arranged in sequence from an object side to an image side; the rear group comprises a first rear group arranged on a reflection path of the light splitting prism and a second rear group arranged on a transmission path of the light splitting prism; the magnification of an optical path structure composed of the front group and the first rear group is X1, the magnification of an optical path structure composed of the front group and the second rear group is X2, and X1X2. The optical system can simultaneously support the connection of two cameras for detection, can amplify and quickly capture the appearance size or overall shape of a target object, can focus and measure a more micro part with high precision, and greatly improves the test efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of machine vision lens, and in particular to a high-precision measurement lens and an optical system thereof. BACKGROUND

[0002] With the rapid development of the machine vision industry, the image instrument based on visual detection can realize accurate measurement and analysis of product appearance size, shape and surface features, and is rapidly popularized in the industrial manufacturing field, such as 3C electronic factories and precision hardware processing plants. However, the current lens can only realize one function, either detecting the size and appearance of the workpiece in a larger field of view or realizing high-precision measurement of micro workpieces in a very small field of view, and cannot achieve both obtaining the appearance size of the workpiece and focusing on obtaining the micro local features of the workpiece.

[0003] Therefore, under the premise of being able to magnify and quickly capture the appearance size or overall shape of the target object, how to improve the magnification of the measurement lens to meet the demand for high-precision measurement of local features has become a technical problem to be solved in the field.

[0004] The above information is given as background information only to assist with an understanding of the present disclosure, and should not be taken as an acknowledgement or admission that any of the above form part of the prior art with respect to the present disclosure. SUMMARY

[0005] The purpose of the present application is to provide a high-precision measurement lens and an optical system thereof to solve or at least partially solve the technical problems existing in the prior art.

[0006] To achieve this purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides an optical system of a high-precision measurement lens, comprising a front group, a light splitting prism and a rear group arranged in order from an object side to an image side; the rear group comprises a first rear group arranged on a reflection path of the light splitting prism, and a second rear group arranged on a transmission path of the light splitting prism;

[0008] The front group comprises a first lens with positive focal power, a second lens with negative focal power, a third lens with positive focal power, a fourth lens with positive focal power, a fifth lens with positive focal power, and a sixth lens with negative focal power;

[0009] The first rear group comprises a first diaphragm, a seventh lens with negative focal power, an eighth lens with positive focal power, a ninth lens with positive focal power, and a tenth lens with positive focal power; wherein the first diaphragm is located at the common focal point of the front group and the lens group of the first rear group, forming a double-telecentric structure;

[0010] The second rear group comprises a second diaphragm, an eleventh lens with negative optical power, a twelfth lens with positive optical power, a thirteenth lens with positive optical power, and a fourteenth lens with positive optical power; the second diaphragm is located at the common focal point of the front group and the second rear group, forming a double-telecentric architecture;

[0011] The magnification of the optical path structure composed of the front group and the first rear group is X1, and the magnification of the optical path structure composed of the front group and the second rear group is X2, and X1X2.

[0012] Optionally, the combined focal length of the front group is f 100 , the combined focal length of the first rear group is f 200 , and the combined focal length of the second rear group is f 300 .

[0013] f 100 , f 200 , and f 300 respectively satisfy the following relationships:

[0014] 0.35<|f 200 / f 100 |<0.7; and 1.25<|f 300 / f 100 |<1.75.

[0015] Optionally, the first lens and the second lens form a cemented lens U1, and the fifth lens and the sixth lens form a cemented lens U2.

[0016] The combined focal length of the front group is f 100 , the focal length of the third lens is f3, and f 100 and f3 satisfy the relationship: 0.3<|f 100 / f3|<0.9.

[0017] The focal length of the fourth lens is f4, and f 100 and f4 satisfy the relationship: 0.2<|f 100 / f4|<0.6.

[0018] The focal length of the cemented lens U1 is f U1 , and f 100 and f U1 satisfy the relationship: |f 100 / f U1 |<0.15.

[0019] The focal length of the cemented lens U2 is f U2 ; and f 100 and f U2 satisfy the relationship: 0.45<|f 100 / f U2 |<0.85.

[0020] Optionally, the seventh lens and the eighth lens constitute a cemented lens U3; the eleventh lens and the twelfth lens constitute a cemented lens U4;

[0021] The combined focal length of the first rear group is f 200 The focal length of the cemented lens U3 is f U3 , f 200 and f U3 satisfy the relationship: 0.2<|f 200 / f U3 |<0.8;

[0022] The focal length of the ninth lens is f9, f 200 and f9 satisfy the relationship: 0.48<|f 200 / f9|<0.88;

[0023] The focal length of the tenth lens is f 10 , f 200 and f 10 satisfy the relationship: 0.3<|f 200 / f 10 |<0.7;

[0024] The combined focal length of the second rear group is f 300 , the focal length of the cemented lens U4 is f U4 , f 300 and f U4 satisfy the relationship: 1.5<|f 300 / f U4 |<2.5;

[0025] The focal length of the thirteenth lens is f 13 , f 300 and f 13 satisfy the relationship: 1<|f 300 / f 13 |<1.7;

[0026] The focal length of the fourteenth lens is f 14 , f 300 and f 14 satisfy the relationship: 0.2<|f 300 / f 14 |<0.8.

[0027] Optionally, the first lens and the fourth lens are both double-convex lenses, the second lens, the fifth lens and the sixth lens are all meniscus lenses, and the third lens is a plano-convex lens or a meniscus lens.

[0028] Optionally, the ninth lens and the tenth lens are both meniscus lenses;

[0029] The eleventh lens is a double-concave lens, the twelfth lens is a double-convex lens, the thirteenth lens is a meniscus lens, and the fourteenth lens is a meniscus lens or a plano-convex lens.

[0030] Optionally, the light-splitting prism is a semi-transmissive and semi-reflective prism.

[0031] Optionally, the fifth lens, the eighth lens, the ninth lens, the twelfth lens and the thirteenth lens are all made of crown glass.

[0032] Optionally, the apertures of the first diaphragm and the second diaphragm are both circular holes, and the centers of the two apertures are both on the optical axis of the optical system.

[0033] In a second aspect, the present application provides a high-precision measurement lens, comprising the optical system of the high-precision measurement lens as described above.

[0034] Compared with the prior art, the present application has the following beneficial effects:

[0035] The optical system of the high-precision measurement lens provided by the present application has two light path structures with different magnification ratios, can simultaneously support the connection of two cameras for detection, can magnify and quickly capture the appearance size or overall shape of a target object, and can also perform high-precision measurement on a part requiring more fine details, thereby greatly improving the test efficiency.

[0036] The present application has other characteristics and advantages, which will be apparent or will be described in detail in the accompanying drawings and subsequent detailed description incorporated herein, which together serve to explain the specific principles of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0038] Figure 1 is a structural schematic diagram of the optical system of the high-precision measurement lens provided by the embodiment of the present application.

[0039] Figure 2 is a structural schematic diagram of the front group of the optical system of the high-precision measurement lens provided by the embodiment of the present application.

[0040] Figure 3is a structural schematic view of a rear group of an optical system of a high-precision measurement lens provided by an embodiment of the present application.

[0041] Figure 4 is a structural schematic view of another rear group of an optical system of a high-precision measurement lens provided by an embodiment of the present application.

[0042] Figure 5 is a light path schematic view of an optical system of a high-precision measurement lens provided by an embodiment of the present application.

[0043] Figure 6 is an MTF diagram of an optical system of a low-magnification measurement lens provided by an embodiment of the present application.

[0044] Figure 7 is an MTF diagram of an optical system of a high-magnification measurement lens provided by an embodiment of the present application.

[0045] Figure 8 is a distortion schematic view of an optical system of a low-magnification measurement lens provided by an embodiment of the present application.

[0046] Figure 9 is a distortion schematic view of an optical system of a high-magnification measurement lens provided by an embodiment of the present application. DETAILED DESCRIPTION

[0047] To make the possible application scenarios, technical principles, specific schemes that can be implemented, purposes and effects that can be achieved of the present application clear, the following will be described in detail in combination with the specific embodiments listed and the accompanying drawings. The embodiments described in the present text are only used to more clearly illustrate the technical schemes of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0048] In the present text, the term “embodiment” means that the specific features, structures or characteristics described in combination with the embodiments can be contained in at least one embodiment of the present application. The term “embodiment” appearing at various positions in the specification does not necessarily refer to the same embodiment, and does not particularly limit the independence or association between other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, each technical feature mentioned in each embodiment can be combined in any way to form a corresponding implementable technical scheme.

[0049] Unless otherwise defined, the meanings of the technical terms used in the present text are the same as those commonly understood by the person skilled in the art to which the present application belongs; the use of related terms in the present text is only for the purpose of describing specific embodiments, and is not intended to limit the present application.

[0050] In the description of the present application, the phrase "and / or" is a description of a logical relationship between objects, which means that there can be three relationships, for example, A and / or B, which means that there are three cases: A exists, B exists, and A and B exist at the same time. In addition, the character " / " herein generally represents that the associated objects before and after are an "or" logical relationship.

[0051] In the present application, the terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual quantity, primary and secondary, or order relationship between the entities or operations.

[0052] In the present application, without more limitation, the "includes", "contains", "has" or other similar expressions used in the sentence are intended to cover non-exclusive inclusion, and these expressions do not exclude the presence of other elements in the process, method or product including the described elements, so that the process, method or product including a series of elements can not only include those limited elements, but also include other elements not explicitly listed, or also include the elements inherent in such process, method or product.

[0053] As the same understanding as in the "Guidelines for Examination", in the present application, the expressions such as "greater than", "less than", "exceed" are understood as not including the number; the expressions such as "above", "below", "within" are understood as including the number. In addition, in the description of the embodiments of the present application, the meaning of "multiple" is more than two (including two), and similar expressions related to "multiple" are also understood in this way, for example, "multiple groups", "multiple times" and the like, unless otherwise explicitly limited.

[0054] In the description of the embodiments of the present application, the spatial-related expressions used, such as "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "vertical", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or the drawings, and are only for the convenience of describing the specific embodiments of the present application or for the reader to understand, and do not indicate or imply that the indicated device or component must have a specific position, a specific orientation, or be constructed or operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0055] Unless otherwise clearly indicated or implied, the terms "mount", "connect", "connection", "fixed", "set", etc., used in the description of the embodiments of the present application are to be construed broadly and are not limited to the meanings of these terms as currently used in the art. For example, the term "connection" can be a fixed connection, or detachable connection, or integral setting; it can be mechanical connection, or electrical connection, or communication connection; it can be direct connection, or indirect connection via an intermediate medium; it can be the internal communication of two elements, or the interaction relationship between two elements. For those skilled in the art of the present application, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0056] Embodiment one:

[0057] Please refer to Figures 1-4 , Figure 1 is a structural schematic diagram of an optical system of a high-precision measurement lens provided by an embodiment of the present application, Figure 2 is a structural schematic diagram of a front group 100 of an optical system of a high-precision measurement lens provided by an embodiment of the present application, Figure 3 is a structural schematic diagram of a rear group of an optical system of a high-precision measurement lens provided by an embodiment of the present application, Figure 4 is a structural schematic diagram of another rear group of an optical system of a high-precision measurement lens provided by an embodiment of the present application;

[0058] As shown in Figure 1 , the optical system comprises:

[0059] a front group 100, a light splitting prism and a rear group arranged in order from an object side to an image side; the rear group comprises a first rear group 200 arranged on a reflection path of the light splitting prism, and a second rear group 300 arranged on a transmission path of the light splitting prism;

[0060] As shown in Figure 2 , the front group 100 comprises a first lens 1 with positive refractive power, a second lens 2 with negative refractive power, a third lens 3 with positive refractive power, a fourth lens 4 with positive refractive power, a fifth lens 5 with positive refractive power, and a sixth lens 6 with negative refractive power;

[0061] As shown in Figure 3 , the first rear group 200 comprises a first diaphragm, a seventh lens 7 with negative refractive power, an eighth lens 8 with positive refractive power, a ninth lens 9 with positive refractive power, and a tenth lens 10 with positive refractive power; wherein the first diaphragm is located at the common focal point of the front group 100 and the lens group of the first rear group 200, forming a double-telecentric architecture;

[0062] As shown in Figure 4As shown, the second rear group 300 comprises a second diaphragm, an eleventh lens 11 with negative optical power, a twelfth lens 12 with positive optical power, a thirteenth lens 13 with positive optical power, and a fourteenth lens 14 with positive optical power; the second diaphragm is located at the common focal point of the front group 100 and the second rear group 300, forming a double telecentric architecture.

[0063] The magnification of the optical path structure composed of the front group 100 and the first rear group 200 is X1, and the magnification of the optical path structure composed of the front group 100 and the second rear group 300 is X2; X1 < X2.

[0064] For ease of understanding, please continue to refer to Figure 5 , Figure 5 is a schematic diagram of an optical path of an optical system of a high-precision measurement lens provided by an embodiment of the present application.

[0065] In the present embodiment, the first rear group 200 is placed along the reflection light direction of the beam splitter prism (i.e. BS in Figure 1 ), and the rear group 300 is placed along the transmission light direction of the beam splitter prism; the first diaphragm (i.e. S1 in Figure 3 ) S1 is located at the common focal point of the front group 100 lens group and the rear group 200 lens group, forming a double telecentric architecture, and the second diaphragm (i.e. S2 in Figure 4 ) is located at the common focal point of the front group 100 lens group and the rear group 300 lens group, forming a double telecentric architecture, thereby reducing the measurement error.

[0066] Further, the combined focal length of the front group 100 is f 100 , the combined focal length of the first rear group 200 is f 200 , and the combined focal length of the second rear group 300 is f 300 .

[0067] f 100 , f 200 , and f 300 respectively satisfy the following relationships:

[0068] 0.35 < |f 200 / f 100 | < 0.7; and 1.25 < |f 300 / f 100 | < 1.75.

[0069] Specifically, the first lens 1 and the second lens 2 form a cemented lens U1, and the fifth lens 5 and the sixth lens 6 form a cemented lens U2.

[0070] The combined focal length of the front group 100 is f 100 , the focal length of the third lens 3 is f3, and f 100 and f3 satisfy the relationship: 0.3 < |f 100|f3| < 0.9;

[0071] The focal length of the fourth lens 4 is f4, f 100 and f4 satisfy the relationship: 0.2 < |f 100 | < 0.6.

[0072] The focal length of the cemented lens U1 is f U1 , f 100 and f U1 satisfy the relationship: |f 100 | < 0.15. U1

[0073] The focal length of the cemented lens U2 is f U2 ; f 100 and f U2 satisfy the relationship: 0.45 < |f 100 | < 0.85. U2

[0074] In the embodiment, the cemented lens U1 bears a small optical power, and the light rays close to the optical axis pass through the cemented lens U1, and the cemented surface of the cemented lens U1 can correct the astigmatism and higher-order aberrations of the optical system, and in combination with the third lens 3, the chromatic aberration of the system (especially a high-power system) can be effectively corrected; the fourth lens 4 has a positive optical power, and shares the deflection light ability of the third lens 3, which is beneficial to compress the system length, and at the same time, the incident angle of the light rays is not too large, which reduces the off-axis aberration, and a certain interval between the third lens 3 and the fourth lens 4 is also beneficial to correct the aberration of the system.

[0075] More specifically, the seventh lens 7 and the eighth lens 8 form a cemented lens U3; the eleventh lens 11 and the twelfth lens 12 form a cemented lens U4;

[0076] The combined focal length of the first rear group 200 is f 200 , the focal length of the cemented lens U3 is f U3 , f 200 and f U3 satisfy the relationship: 0.2 < |f 200 | < 0.8. U3

[0077] The focal length of the ninth lens 9 is f9, f 200 and f9 satisfy the relationship: 0.48 < |f 200 | < 0.88.

[0078] The focal length of the tenth lens 10 is f 10 , f 200 and f 10 satisfy the relationship: 0.3 < |f 200 | < 0.7. 10 ​​​​

[0079] The combined focal length of the second group 300 is f 300 The focal length of the cemented lens U4 is f U4 f 300 and f U4 satisfy the relationship: 1.5 < |f 300 / f U4 | < 2.5;

[0080] The focal length of the thirteenth lens 13 is f 13 f 300 and f 13 satisfy the relationship: 1 < |f 300 / f 13 | < 1.7;

[0081] The focal length of the fourteenth lens 14 is f 14 f 300 and f 14 satisfy the relationship: 0.2 < |f 300 / f 14 | < 0.8.

[0082] In the embodiment, the tenth lens 10 is made of high refractive material and has a meniscus structure facing the image plane, which is beneficial to correcting the coma, astigmatism and field curvature of the system.

[0083] More specifically, in the embodiment, the first lens 1 and the fourth lens 4 are both double convex lenses, the second lens 2, the fifth lens 5 and the sixth lens 6 are all meniscus lenses, and the third lens 3 is a plano-convex lens or a meniscus lens.

[0084] The ninth lens 9 and the tenth lens 10 are both meniscus lenses.

[0085] The eleventh lens 11 is a double concave lens, the twelfth lens 12 is a double convex lens, the thirteenth lens 13 is a meniscus lens, and the fourteenth lens 14 is a meniscus lens or a plano-convex lens.

[0086] In the embodiment, each lens in the optical system is a glass spherical lens.

[0087] In the embodiment, the light splitting prism is a semi-transmissive semi-reflective prism.

[0088] As a preferred embodiment, in the embodiment, the fifth lens 5, the eighth lens 8, the ninth lens 9, the twelfth lens 12 and the thirteenth lens 13 are all made of crown glass. The use of the crown glass lens combination is more beneficial to correcting the chromatic aberration of the system.

[0089] As an optional embodiment, in the embodiment, the apertures of the first diaphragm and the second diaphragm are both circular holes, and the centers of the two apertures are both on the optical axis (O) of the optical system. Figure 1The two dashed lines in the diagram represent optical axes, and the centers of the two apertures are located on the two optical axes respectively.

[0090] Understandably, the aperture value of the stop needs to be adjusted according to the specific application scenario.

[0091] For example, to verify the above optical system, this example also provides a specific test case, as follows:

[0092] The data for the low-magnification measurement optical system consisting of the front group 100 and the first rear group 200 are shown in Table 1 below:

[0093] Table 1

[0094]

[0095]

[0096] It should be noted that in Table 1, "front surface" corresponds to... Figure 2 or Figure 3 The left surface of the lens or lens group corresponds to the middle surface, while the rear surface corresponds to the left surface. Figure 2 or Figure 3 The right side surface of the corresponding lens or lens group; or it can be understood as: the object surface in Figure 1 On the left, the image plane (or image plane 1) is... Figure 1 On the upper side, the surface closer to the object is called the "front surface", and the surface closer to the image is called the "rear surface".

[0097] The data for the high-magnification measurement optical system consisting of the front group 100 and the second rear group 300 are shown in Table 2 below:

[0098] Table 2

[0099]

[0100] It should be noted that in Table 2, "front surface" corresponds to... Figure 1 or Figure 4 The left surface of the lens or lens group corresponds to the middle surface, while the rear surface corresponds to the left surface. Figure 1 The right side surface of the corresponding lens or lens group; or it can be understood as: the object surface in Figure 1 On the left, the image plane (or image plane 2) is... Figure 1 The surface on the right side, closer to the object side, is called the "front surface," and the surface closer to the image side is called the "rear surface."

[0101] In this embodiment, the combined focal length f of the front group 100 100 =68mm, the focal length of the third lens 3 is f3=113mm, the focal length of the fourth lens 4 is f4=169mm, and the focal length of the cemented lens U1 is f U1= 579 mm, focal length f of cemented lens U2 U2 = -105 mm; combined focal length f of first rear group 200 200 = 34 mm, focal length f9 of ninth lens 9 = 50 mm, focal length f of tenth lens 10 10 = 69 mm, focal length f of cemented lens U3 U3 = -58 mm;

[0102] combined focal length f of second rear group 300 300 = 103 mm, focal length f of thirteenth lens 13 13 = 78 mm, focal length f of fourteenth lens 14 14 = 178 mm, focal length f of cemented lens U4 U4 = -54 mm.

[0103] Substituting the above parameters into the calculation, we get:

[0104] |f 200 / f 100 | = 0.5, |f 300 / f 100 | = 1.515, |f 100 / f3| = 0.602, |f 100 / f4| = 0.402, |f 100 / f U1 | = 0.117, |f 100 / f U2 | = 0.648, |f 200 / f U3 | = 0.586, |f 200 / f9| = 0.68, |f 200 / f 10 | = 0.493, |f 300 / f U4 | = 1.907, |f 300 / f 13 | = 1.321, |f 300 / f 14 | = 0.579;

[0105] From the above calculation results, it can be seen that the settings of the above parameters all satisfy the corresponding relationship:

[0106] 0.35 < |f 200 / f 100 | < 0.7, 1.25 < |f 300 / f 100 | < 1.75, 0.3 < |f 100 / f3| < 0.9, 0.2 < |f 100 / f4| < 0.6, |f100 / f U1 |<0.15, 0.45<|f 100 / f U2 |<0.85, 0.2<|f 200 / f U3 |<0.8, 0.48<|f 200 / f9|<0.88, 0.3<|f 200 / f 10 |<0.7, 1.5<|f 300 / f U4 |<2.5, 1<|f 300 / f 13 |<1.7, 0.2<|f 300 / f 14 |<0.8.

[0107] In this embodiment, the optical parameters of the low magnification measurement lens composed of the front group 100 and the first rear group 200 are shown in the following Table Three:

[0108] Table Three

[0109] Working distance WD 114 mm Magnification 0.5x Field of view Φ 36.8 mm Target surface 1.1 inch MTF30 > 135 lp / mm Telecentricity <0.1°

[0110] Please refer to Figure 6 and Figure 8 , Figure 6 the MTF diagram of the optical system of the low magnification measurement lens provided by the embodiment of the application, Figure 8 the distortion schematic diagram of the optical system of the low magnification measurement lens provided by the embodiment of the application;

[0111] According to experimental verification, the distortion of the optical system of the low magnification measurement lens is less than 0.03%.

[0112] In this embodiment, the optical parameters of the high magnification measurement lens composed of the front group 100 and the second rear group 300 are shown in the following Table Four:

[0113] Table Four

[0114] Working distance WD 114 mm Magnification 1.5x Field of view Φ 12.3 mm Target surface 1.1 inch MTF30 > 100 lp / mm Telecentricity <0.1°

[0115] Please refer to Figure 7 and Figure 9 , Figure 7 the MTF diagram of the optical system of the high magnification measurement lens provided by the embodiment of the application, Figure 9 the distortion schematic diagram of the optical system of the high magnification measurement lens provided by the embodiment of the application;

[0116] According to experimental verification, the distortion of the optical system of the high magnification measurement lens is less than 0.001%.

[0117] In summary, the embodiment has two different magnification optical path structures of high and low magnification by the structure design of the optical system, the magnification of the high magnification optical path structure can reach 1.5 times; two cameras can be connected to detect at the same time, the appearance size or overall shape of the target object can be enlarged and quickly captured by the low magnification optical path structure, and high-precision measurement is switched to the high magnification optical path structure for more detailed local measurement, which greatly improves the test efficiency.

[0118] Embodiment two:

[0119] The embodiment provides a high-precision measurement lens, comprising the optical system of the high-precision measurement lens according to the embodiment one.

[0120] Based on the detailed description of the optical system in the embodiment one, the embodiment two will not be repeated.

[0121] In summary, the embodiment has two different magnification optical path structures of high and low magnification by the structure design of the optical system, the magnification of the high magnification optical path structure can reach 1.5 times; two cameras can be connected to detect at the same time, the appearance size or overall shape of the target object can be enlarged and quickly captured by the low magnification optical path structure, and high-precision measurement is switched to the high magnification optical path structure for more detailed local measurement, which greatly improves the test efficiency.

[0122] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some technical features; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An optical system for a high-precision measuring lens, characterized in that, The device consists of a front group (100), a beam splitter, and a rear group arranged sequentially from the object side to the image side; the rear group consists of a first rear group (200) located on the reflection path of the beam splitter and a second rear group (300) located on the transmission path of the beam splitter. The front group (100) consists of a first lens (1) with positive optical power, a second lens (2) with negative optical power, a third lens (3) with positive optical power, a fourth lens (4) with positive optical power, a fifth lens (5) with positive optical power, and a sixth lens (6) with negative optical power. The first rear group (200) consists of a first aperture stop, a seventh lens (7) with negative optical power, an eighth lens (8) with positive optical power, a ninth lens (9) with positive optical power, and a tenth lens (10) with positive optical power; wherein, the first aperture stop is located at the common focal point of the front group (100) and the first rear group (200) lens groups, forming a double telecentric structure; The second rear group (300) consists of a second aperture stop, an eleventh lens (11) with negative optical power, a twelfth lens (12) with positive optical power, a thirteenth lens (13) with positive optical power, and a fourteenth lens (14) with positive optical power; the second aperture stop is located at the common focal point of the front group (100) and the second rear group (300), forming a double telecentric structure; The magnification of the optical path structure composed of the front group (100) and the first rear group (200) is X1, and the magnification of the optical path structure composed of the front group (100) and the second rear group (300) is X2; X1 <X2; The combined focal length of the front group (100) is f 100 The combined focal length of the first rear group (200) is f. 200 The combined focal length of the second rear group (300) is f. 300 ; f 100 f 200 and f 300 They respectively satisfy the following relations: 0.35<|f 200 / f 100 |<0.7;1.25<|f 300 / f 100 |<1.75; The first lens (1) and the second lens (2) form a cemented lens U1, and the fifth lens (5) and the sixth lens (6) form a cemented lens U2; The combined focal length of the front group (100) is f 100 The focal length of the third lens (3) is f3, f 100 The relationship between f and f3 is: 0.3 < |f 100 / f3|<0.9; The focal length of the fourth lens (4) is f4, f 100 The relationship between f and f4 is: 0.2 < |f 100 / f4|<0.6; The focal length of the cemented lens U1 is f U1 f 100 and f U1 Satisfy the relation: |f 100 / f U1 |<0.15; The focal length of the cemented lens U2 is f U2 ;f 100 and f U2 The relation is satisfied: 0.45 < |f 100 / f U2 |<0.

85.

2. The optical system of a high-precision measuring lens according to claim 1, characterized in that, The seventh lens (7) and the eighth lens (8) form a cemented lens U3; the eleventh lens (11) and the twelfth lens (12) form a cemented lens U4; The combined focal length of the first rear group (200) is f. 200 The focal length of the cemented lens U3 is f. U3 f 200 and f U3 The relation is satisfied: 0.2 < |f 200 / f U3 |<0.8; The focal length of the ninth lens (9) is f9, f 200 The relationship between f and f9 is: 0.48 < |f 200 / f9|<0.88; The focal length of the tenth lens (10) is f 10 f 200 and f 10 The following relationship is satisfied: 0.3 < |f200 / f10| < 0.7; The combined focal length of the second rear group (300) is f. 300 The focal length of the cemented lens U4 is f. U4 f 300 and f U4 Satisfies the relation: 1.5 < |f 300 / f U4 |<2.5; The focal length of the thirteenth lens (13) is f 13 f 300 and f 13 Satisfies the relation: 1 < |f 300 / f 13 |<1.7; The focal length of the fourteenth lens (14) is f 14 f 300 and f 14 The relation is satisfied: 0.2 < |f 300 / f 14 |<0.

8.

3. The optical system of a high-precision measuring lens according to claim 1, characterized in that, The first lens (1) and the fourth lens (4) are both biconvex lenses, the second lens (2), the fifth lens (5) and the sixth lens (6) are all meniscus lenses, and the third lens (3) is either a plano-convex lens or a meniscus lens.

4. The optical system of a high-precision measuring lens according to claim 2, characterized in that, Both the ninth lens (9) and the tenth lens (10) are meniscus lenses; The eleventh lens (11) is a biconcave lens, the twelfth lens (12) is a biconvex lens, the thirteenth lens (13) is a meniscus lens, and the fourteenth lens (14) is either a meniscus lens or a plano-convex lens.

5. The optical system of a high-precision measuring lens according to claim 1, characterized in that, The beam splitter is a semi-transparent, semi-reflective prism.

6. The optical system of a high-precision measuring lens according to claim 1, characterized in that, The fifth lens (5), the eighth lens (8), the ninth lens (9), the twelfth lens (12), and the thirteenth lens (13) are all made of crown glass.

7. The optical system of a high-precision measuring lens according to claim 1, characterized in that, Both the first and second apertures are circular apertures, and the centers of both apertures are on the optical axis of the optical system.

8. A high-precision measuring lens, characterized in that, An optical system including a high-precision measuring lens as described in any one of claims 1-7.

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