CN215375908U

CN215375908U - Dispersion lens

Info

Publication number: CN215375908U
Application number: CN202121464517.8U
Authority: CN
Inventors: 李一哲; 胡浩
Original assignee: Seizet Technology Shenzhen Co Ltd
Current assignee: Seizet Technology Shenzhen Co Ltd
Priority date: 2021-06-29
Filing date: 2021-06-29
Publication date: 2021-12-31
Anticipated expiration: 2031-06-29

Abstract

A dispersion lens comprises a lens cone and a dispersion objective optical path, wherein the dispersion objective optical path comprises a first lens group and a second lens group which are sequentially arranged from an object side to an image side, the first lens group is used for controlling the object side to be telecentric and carrying out primary dispersion on modulation detection light projected by an optical fiber array, the second lens group is used for controlling the image side to be telecentric and carrying out secondary dispersion on the modulation detection light, and the long focal length of the first lens group is matched with the short focal length of the second lens group to be used for zoom control from the object side to the image side, wherein the object/image side zoom magnification is f1/f2, the lens cone comprises a first lens frame used for fixing the first lens group, a second lens frame used for fixing the second lens group and a lens base connecting the first lens frame and the second lens frame, the first lens group and the second lens group are respectively fixed by the corresponding first lens frame and the second lens frame and then are matched by the lens base to realize focal length adjustment between the first lens frame and the second lens frame, the device has the advantages of ensuring the brightness and the accuracy consistency of the measuring light spot projected onto the measured object, along with simple integral structure and convenience in installation and debugging.

Description

Dispersion lens

Technical Field

The utility model belongs to the field of optics, and particularly relates to a dispersion lens for line spectrum confocal.

Background

With the rapid development of precision and ultra-precision manufacturing industry, the demand for high-precision detection is higher and higher, and thus high-precision displacement sensors are also produced. The precision of the ultra-precise displacement sensor can reach the micron level; although the traditional contact measurement has higher precision, the surface of a measured object may be scratched, and when the measured object is a weak rigid or soft material, the contact measurement also causes elastic deformation, which introduces measurement errors.

The spectrum confocal sensor is a device for establishing a corresponding relation between distance and wavelength by an optical dispersion principle and decoding spectrum information by a spectrometer so as to obtain position information, as shown in fig. 1, light emitted by a light source can be approximately regarded as a point light source after passing through an optical fiber coupler, the light is subjected to spectrum dispersion after being focused by a collimating and dispersing objective lens, monochromatic light focuses which are continuously distributed along different wavelengths in the optical axis direction are formed on an image surface, and the distances from the monochromatic light focus of each wavelength to a measured object are different. When the measured object is at a certain position in the measuring range, only the light with specific wavelength is in a focusing state on the measured surface, the light with the wavelength can be reflected back to the optical fiber coupler from the surface of the measured object and enter the spectrometer because the light meets the confocal condition, while the light with other wavelengths is in a defocusing state on the surface of the measured object, and the distribution of the reflected light at the light source is far larger than the diameter of the fiber core of the optical fiber, so most of the light with other wavelengths cannot enter the spectrometer. And decoding by a spectrometer to obtain the wavelength value of the maximum light intensity of the echo, thereby measuring the distance value corresponding to the measured object. The confocal technology is adopted, so the method has good chromatographic characteristics, improves the resolution and is insensitive to the characteristics of the measured object and the ambient stray light.

In the spectrum confocal sensor, a dispersion lens is a core device of the spectrum confocal sensor, and parameters such as resolution, measuring range, line length and the like are determined. However, the current dispersive lens has the following design difficulties:

(1) the problem of uniformity of the optical channels at non-central positions, that is, the problem of uniformity of spot sizes, brightness, and the like of a plurality of optical channels (optical fibers). For a point-spectrum confocal system, only one optical fiber is arranged to form one optical channel, and the position of the optical channel (optical fiber) is at the position of an optical axis, so that only on-axis aberration needs to be corrected, and the requirement of consistency is absent. However, for a line spectrum confocal system, the line spectrum confocal system includes more than one hundred optical channels, each optical channel needs to generate dispersion within a certain range, and since the number of optical channels is large, the optical channel located at a non-optical axis is far from an optical axis, when dispersion is performed, besides on-axis aberration correction, coma, field curvature, astigmatism, distortion and the like need to be corrected to ensure that the brightness and the spot size of each optical channel are consistent as much as possible, so how to design an optical path, especially a dispersion lens, to ensure the brightness uniformity and the precision uniformity of the hundreds of optical channels needs to be focused.

(2) The length of the line length L of the line spectrum confocal sensor system is in conflict with the resolution of the measuring light spot, for the line spectrum confocal sensor system, the longer the line length is, the better the length is, the length which can be scanned at one time is determined by the projected line length, and under the condition of determining the scanning area of the measured object, the longer the line length L is, the larger the area is, the faster the corresponding scanning speed is, and the working efficiency is correspondingly improved; each optical channel is imaged at one point on the surface of the object, namely a measuring light spot is formed, and the smaller the measuring light spot is, the higher the system resolution and precision are, namely the smaller the resolvable measured object size is, the more suitable occasions are.

The size of each measuring spot projected onto the measured object by each dispersive objective lens is related to the light passing size of the optical channel, the smaller the light passing size is, the smaller the measuring spot is, and the higher the resolution is, and the smaller the optical fiber diameter R is (the smaller the corresponding light passing size is generally), the shorter the corresponding line length L is. The problem can be solved by increasing the number of optical channels, but if the number of optical channels is simply increased, the contradiction between the line length and the resolution cannot be solved, because the number of optical channels (optical fibers) is increased, the problem of consistency of the optical channels at the non-central position is introduced, which causes the difficulty of designing the optical path to be overlarge, and meanwhile, the problems of high cost, overlarge volume and overlarge weight exist.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a dispersion lens to solve the problems in the prior art.

In order to achieve the above object, the present invention provides a dispersion lens for dispersing light emitted from a light source, the dispersion lens comprising a lens barrel and a dispersion objective optical path, the dispersion objective optical path being disposed in the lens barrel; the dispersion objective optical path includes first lens group and the second lens group of following object space to image space and arranging in proper order, first lens group is used for controlling the object space telecentricity and detects the light and carry out preliminary dispersion to the modulation that the fiber array throws, the second lens group is used for controlling the image space telecentricity and right the modulation detects the light and carries out the secondary dispersion, and the via the long focal length of first lens group with the short focal length cooperation of second lens group is used for the object space extremely image space zooming control, wherein, object space/image space zooming multiplying power is f1/f2, f1 is the focal length of first lens group, f2 is the focal length of second lens group, the object space is fiber array, the image space is the line length that dispersion objective throws. The lens barrel comprises a first lens frame used for fixing the first lens group, a second lens frame used for fixing the second lens group and a lens base used for connecting the first lens frame and the second lens frame, and the first lens group and the second lens group are respectively fixed through the corresponding first lens frame and the second lens frame and then are matched through the lens base to realize the adjustment of focal length between the first lens group and the second lens group.

Preferably, the inner walls of the first mirror frame and the second mirror frame are both provided with a black coating.

Preferably, the first mirror frame and the mirror base are fixed by a pin shaft and a screw through a channel, and the mirror base and the second mirror frame are fixed by threaded connection.

Preferably, the focal length of the first lens group is a long focal length, and the first lens includes a first lens, a second lens and a third lens which are coaxially disposed, where the first lens is configured to compress a beam aperture of the modulated detection light to control object telecentricity, and the second lens is configured to balance coma, astigmatism and distortion of the modulated detection light, and further compress the beam to generate partial dispersion; the third lens is used for eliminating field curvature and distortion of the modulation detection light, is matched with the first lens and is used for controlling object space telecentricity, and the focal length of the first lens group is controlled to be a long focal length.

Preferably, the first lens is a positive long focal length lens, the focal length range is 200mm to 250mm, the second lens is a positive long focal length lens, the focal length range is 100mm to 150mm, the third lens is a negative small focal length lens, and the focal length range is-40 mm to 18 mm.

Further, the first lens is a positive meniscus lens and is arranged towards the object space, the second lens is a positive meniscus lens and is arranged towards the object space, and the third lens is a negative meniscus lens and is arranged towards the object space.

Preferably, the second lens group includes a first lens unit, a second lens unit, and a third lens unit coaxially disposed; the first lens unit is used for eliminating spherical aberration of the modulation detection light, controlling the focal length of the second lens group and controlling image space telecentricity; the second lens unit is used for balancing spherical aberration and coma aberration of the modulation detection light, compressing a beam divergence angle of the modulation detection light and further generating dispersion; the third lens unit is configured to remove residual spherical aberration, coma aberration, and astigmatism of the modulated detection light.

Further, the first lens unit comprises a fourth lens, the fourth lens is a negative middle focal length lens, and the focal length range is from-100 mm to-80 mm; the second lens unit comprises a fifth lens, a sixth lens and a seventh lens which are sequentially connected, wherein the fifth lens is a positive long focal length lens, the focal length range is 110 mm-160 mm, the sixth lens is a positive long focal length lens, the focal length range is 120 mm-170 mm, the seventh lens is a positive long focal length lens, and the focal length range is 150 mm-200 mm; the third lens unit includes an eighth lens and a ninth lens connected in series; the eighth lens is a positive long-focus lens, the focal length range is 160mm to 210mm, the ninth lens is a positive short-focus lens, and the focal length range is 30mm to 60 mm.

Further, the fourth lens is a biconcave lens; the fifth lens is a positive meniscus lens and is arranged towards the image space, the sixth lens is a double-convex lens, and the seventh lens is a positive meniscus lens and is arranged towards the object space; the eighth lens is a positive meniscus lens and is arranged towards the object space, and the ninth lens is a positive meniscus lens and is arranged towards the object space.

Preferably, the zoom magnification of the object space and the image space is between 0.04 and 0.5.

Preferably, the length of the optical fiber array is 25mm-85 mm.

According to the dispersion objective lens disclosed by the utility model, a plurality of point light sources of an external optical fiber array are used as an object space, zooming is realized through the matching of the first lens group and the second lens group of the dispersion objective lens, and a reduced line is formed on an image surface, wherein the specific zooming magnification is f2/f1(f1 is the focal length of the first lens group, and f2 is the focal length of the second lens group), because the dispersion objective lens uses a double telecentric optical path to generate dispersion, the object space telecentricity is that for an optical path with non-coaxial edges, a principal ray and an on-axis ray are the same and parallel with an optical axis, and the brightness among data points is ensured to be close; the image space telecentricity enables the chief ray of the marginal field of view to be parallel to the optical axis as the chief ray of the on-axis field of view, and ensures that the axes of the cone angles of the light reaching the target point are consistent, thereby ensuring the brightness and the accuracy consistency of the measuring light spot projected on the measured object. Simultaneously, first battery of lens and second battery of lens are respectively through first picture frame, second picture frame fixed mounting back, realize the fixed of the two and focus adjustment through the microscope base, and overall structure is simple, is convenient for install and debug.

Drawings

FIG. 1 is a schematic diagram of the working principle of a line spectrum sensor;

FIG. 2 is a schematic diagram of an embodiment of a dispersion objective lens according to the present invention;

FIG. 3 is a schematic structural diagram of an embodiment of a dispersion objective optical path according to the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and do not limit the scope of the utility model in any way.

Like reference numerals refer to like elements throughout the specification. The expression "and/or" includes any and all combinations of one or more of the associated listed items. In the drawings, the thickness, size, and shape of an object have been slightly exaggerated for convenience of explanation. The figures are purely diagrammatic and not drawn to scale.

It will be further understood that the terms "comprises," "comprising," "includes," "including," "has," "includes" and/or "including," when used in this specification, specify the presence of stated features, steps, integers, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, integers, operations, elements, components, and/or groups thereof.

The terms "substantially", "about" and the like as used in the specification are used as terms of approximation and not as terms of degree, and are intended to account for inherent deviations in measured or calculated values that would be recognized by one of ordinary skill in the art.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

As shown in fig. 2, the present invention discloses a dispersion lens for dispersing light emitted from a light source, wherein the dispersion lens comprises a lens barrel and a dispersion objective optical path, and the dispersion objective optical path is arranged in the lens barrel; the dispersion objective optical path includes first lens group and the second lens group of following object space to image space and arranging in proper order, first lens group is used for controlling the object space telecentricity and detects the light and carry out preliminary dispersion to the modulation that the fiber array throws, the second lens group is used for controlling the image space telecentricity and right the modulation detects the light and carries out the secondary dispersion, and the via the long focal length of first lens group with the short focal length cooperation of second lens group is used for the object space extremely image space zooming control, wherein, object space/image space zooming multiplying power is f1/f2, f1 is the focal length of first lens group, f2 is the focal length of second lens group, the object space is fiber array, the image space is the line length that dispersion objective throws. The lens barrel comprises a first lens frame 21 used for fixing the first lens group, a second lens frame 22 used for fixing the second lens group and a lens base 23 used for connecting the first lens frame 21 and the second lens frame 22, and the first lens group and the second lens group are respectively fixed through the corresponding first lens frame 21 and the second lens frame 22 and then are matched through the lens base 23 to realize the adjustment of the focal length between the first lens group and the second lens group.

The multiple point light sources of the external optical fiber array are used as an object space, zooming is realized through the matching of the first lens group and the second lens group of the dispersion objective lens, and a reduced line is formed on an image surface, wherein the specific zooming magnification is f2/f1(f1 is the focal length of the first lens group, and f2 is the focal length of the second lens group), because the dispersion objective lens uses a double telecentric optical path to generate dispersion, object space telecentricity is that for an optical path with non-coaxial edges, a principal ray and an axial light ray are the same and parallel with an optical axis, and the brightness among data points is ensured to be close; the image space telecentricity enables the chief ray of the marginal field of view to be parallel to the optical axis as the chief ray of the on-axis field of view, and ensures that the axes of the cone angles of the light reaching the target point are consistent, thereby ensuring the brightness and the accuracy consistency of the measuring light spot projected on the measured object. Meanwhile, after the first lens group and the second lens group are respectively fixedly mounted through the first lens frame 21 and the second lens frame 22, the fixation and the focal length adjustment of the first lens group and the second lens group are realized through the lens base 23, so that the whole structure is simple, and the installation and the debugging are convenient.

After linear, dispersed and uniform measuring light spots formed by the dispersive objective lens are projected on a measured object, the linear, dispersed and uniform measuring light spots are matched with a motion platform which is perpendicular to a line and parallel to the line, and high-precision three-dimensional scanning and model reconstruction of a large object can be realized. The modulated detection light is projected to a measured object through the dispersion objective lens, the light wavelengths of the focusing light spots at different heights are different, the modulated detection light returns through the dispersion objective lens according to the original light path again, and the modulated detection light is transmitted to the spectrometer through the optical fiber of the spectrometer so as to form an image capable of judging the wavelength of the echo on the camera, and therefore the height of the corresponding position of the measured object can be calculated according to the wavelength.

In this embodiment, the objective lens with chromatic dispersion uses lens combinations with different curvatures, thicknesses and materials to control monochromatic aberrations including aberrations such as spherical aberration, coma, field curvature, astigmatism and distortion on the basis of enlarging chromatic dispersion as much as possible, so that the system has a diffuse spot close to or reaching a diffraction limit level at different wavelengths, and has a perfect imaging effect on different wavelengths existing in a light source.

Specifically, as shown in fig. 3, the dispersive objective optical path includes a first lens group for controlling object-side telecentricity and a second lens group for controlling image-side telecentricity, where the object side is the optical fiber array of the first light-emitting end, and the image side is the projection light spot of the line spectrum confocal sensor system.

The optical path of the dispersive objective lens disclosed by the utility model generates dispersion by using the double telecentric optical path, and when the optical path is matched with a large-size optical fiber array, the optical path can ensure the brightness and the accuracy consistency of light spots projected to a measured object, and simultaneously improve the length of a line projected by a system as much as possible. In one embodiment, the length of the light source fiber 20 is set to be 25mm to 85mm, and the zoom ratio between the object space of the dispersive objective lens 30 and the image space of the dispersive objective lens 30 is set to be 0.04 to 0.5, so as to improve the length of the line projected by the system as much as possible while ensuring the uniformity of the brightness and accuracy of the light spot projected to the measured object. Of course, the optical path of the dispersive objective lens of the present invention can also be used with an optical fiber array with the size below 25mm, such as a conventional 20mm optical fiber array. Furthermore, the focal length f1 of the first lens group 31 ranges from 500mm to 800mm, and the focal length f2 of the second lens group 32 ranges from 32mm to 250 mm.

In one embodiment, the first lens group includes a first lens L1, a second lens L2, and a third lens L3 coaxially disposed, where the first lens L1 is configured to compress the beam aperture of the modulated detection light, control object-side telecentricity, convert light emitted from the plurality of optical fibers in the first light-emitting end into spatial light and reach the first lens L1, the first lens L1 primarily compresses each beam aperture and reaches the second lens L2, and the second lens L2 is configured to balance coma, astigmatism, and distortion of the modulated detection light, further compress the beam aperture of the modulated detection light, and generate partial dispersion; after the light beam adjusted by the first lens L1 and the second lens L2 reaches the third lens L3, the third lens L3 is used for eliminating curvature of field and distortion of the modulated and detected light, controlling object-side telecentricity, and controlling the focal length of the first lens group to be a long focal length.

The focal length adjustment of the first lens group is realized by adjusting relevant parameters of the first lens L1, the second lens L2 and the third lens L3; and different arrangements of the main functions of the lenses are realized through curvature, thickness and material selection. In this embodiment, the first lens L1 is a positive long focal length lens, the focal length range is 200mm to 250mm, the second lens L2 is a positive long focal length lens, the focal length range is 100mm to 150mm, the third lens L3 is a negative small focal length lens, and the focal length range is-40 mm to 18 mm; furthermore, in the present embodiment, the first lens L1 is a positive meniscus lens disposed toward the object side of the dispersion mirror, the second lens L2 is a positive meniscus lens disposed toward the object side of the dispersion mirror, and the third lens L3 is a negative meniscus lens disposed toward the object side.

In one embodiment, the second lens group includes a first lens unit, a second lens unit, and a third lens unit coaxially disposed; the first lens unit is configured to eliminate spherical aberration of the modulated detection light, control a focal length of the second lens group, and control image-side telecentricity, in this embodiment, the first lens unit includes a fourth lens L4, and the modulated detection light processed by the first lens group passes through the fourth lens L4 to eliminate spherical aberration of the modulated detection light; the second lens unit is used for balancing the spherical aberration and the coma aberration of the modulation detection light, compressing the beam divergence angle of the modulation detection light and further generating dispersion; in the present embodiment, the second lens unit includes a fifth lens L5, a sixth lens L6, and a seventh lens L7, which are coaxially arranged; the third lens unit is configured to remove residual spherical aberration, coma aberration, and astigmatism of the modulated detection light. In the present embodiment, the third lens unit includes an eighth lens L8 and a ninth lens L9 connected in series.

Wherein, the focal length adjustment of the second lens group is realized by adjusting relevant parameters of the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9; and different arrangements of the main functions of the lenses are realized through curvature, thickness and material selection. The fourth lens L4 is a negative middle focal length lens, and the focal length range is-100 mm to-80 mm; the second lens unit comprises a fifth lens L5, a sixth lens L6 and a seventh lens L7 which are sequentially connected, wherein the fifth lens L5 is a positive long focal length lens, the focal length range is 110 mm-160 mm, the sixth lens L6 is a positive long focal length lens, the focal length range is 120 mm-170 mm, the seventh lens L7 is a positive long focal length lens, and the focal length range is 150 mm-200 mm; the third lens unit includes an eighth lens L8 and a ninth lens L9 connected in series; the eighth lens L8 is a positive long focal length lens with a focal length ranging from 160mm to 210mm, and the ninth lens L9 is a positive short focal length lens with a focal length ranging from 30mm to 60 mm.

Further, the fourth lens element L4 is a biconcave lens element, the fifth lens element L5 is a positive meniscus lens element and is disposed toward the image side, the sixth lens element L6 is a biconvex lens element, the seventh lens element L7 is a positive meniscus lens element and is disposed toward the object side, the eighth lens element L8 is a positive meniscus lens element and is disposed toward the object side, and the ninth lens element L9 is a positive meniscus lens element and is disposed toward the object side.

The dispersion objective lens is arranged through a double telecentric structure, object space telecentricity and image space telecentricity are respectively controlled, line light sources in a large range can be equivalent, so that dispersion of uniform line light sources is generated, the brightness and accuracy consistency of measured light spots are guaranteed, zooming is formed by matching of a first lens group focal length f1 and a second lens group focal length f2, the zooming multiplying power beta of the dispersion objective lens can be confirmed by adjusting the ratio of the f1 to the f2, and the control of the linear length of the system is achieved according to actual requirements.

Meanwhile, the dispersion objective lens is matched with the light source optical fiber, so that the angle adaptability, the angle size and the zoom magnification of the system are effectively improvedBeta, object space numerical aperture NA₁In relation to this, the smaller the zoom factor beta is, the smaller the object numerical aperture NA₁The larger the image-side numerical aperture NA₂The larger the angle, the better the angular adaptability.

As shown in the above formula, the realization of large angle adaptability of image space is mainly determined by two aspects, one is to increase the object space aperture NA in the range smaller than the numerical aperture of the optical fiber₁Numerical values can improve the efficiency of the light source, but the difficulty and complexity of optical design are correspondingly greatly increased, and the on-axis aberration and the off-axis aberration are difficult to eliminate; on the other hand, the zoom ratio of the whole dispersive mirror is determined, the smaller the zoom ratio is, the larger the image-side numerical aperture is under the condition that the object-side numerical aperture is fixed, but the zoom ratio is also limited by the transverse resolution of the dispersive mirror, so that the limit is large, and the change is not generally made.

In the line spectrum confocal system, as described above, the zoom ratio of the dispersive objective lens is 0.04-0.5, the ratio of the light passing size d1 of each optical channel to the interval d2 between the optical channels is set to be 0.3-0.7, and the two are matched to ensure that all points on the line are consistent in uniformity and precision under the condition of large line length of the system, and simultaneously realize larger angle adaptability on a target surface, namely that light can return to the original optical fiber channel within the range of 90 degrees +/-35 degrees; the characteristics of large line length, high consistency and large angle are considered;

in the embodiment, the chromatic dispersion objective lens adopts a single group of lenses to generate chromatic aberration, and corrects other chromatic aberration, so that the chromatic dispersion objective lens is convenient to process and simple to produce. Step surfaces are respectively arranged in the first lens frame 21 corresponding to the first lens L1, the second lens L2 and the third lens L3, and the first lens L1, the second lens L2 and the third lens L3 are placed on the corresponding step surfaces, are positioned by matching with the step surfaces through spacing rings, and are screwed and fixed through pressing rings; the inner wall of the second frame 22 is also provided with a step surface corresponding to the fourth lens L4, the fifth lens L5, the sixth lens L6, the seventh lens L7, the eighth lens L8 and the ninth lens L9, and the fourth lens L4 to the ninth lens L9 are positioned by the step surface and the spacer ring of the inner wall of the second frame 22, and then are screwed and fixed by a pressing ring.

After the optical components inside the first lens frame 21 and the second lens frame 22 are mounted, the first lens frame 21 and the second lens frame 22 are positioned and fixed by the lens base 23 to form a complete dispersion lens, in this embodiment, the first lens frame 21 and the lens base 23 are positioned and fixed by a pin shaft and a screw, and the second lens frame 22 and the lens base 23 are positioned and fixed by threaded connection.

Meanwhile, the inner walls of the first lens frame 21 and the second lens frame 22 are both provided with a black coating. In this embodiment, the inner side of the lens barrel is blackened to eliminate the diffracted light of the order.

It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A kind of dispersive lens, is used for making the light that the light source emits take the chromatic dispersion, characterized by that, the said dispersive lens includes lens-barrel and dispersive object lens light path, the said dispersive object lens light path is set up in the said lens-barrel;

the optical path of the dispersive objective lens comprises a first lens group and a second lens group which are sequentially arranged from an object side to an image side, wherein the first lens group is used for controlling the telecentricity of the object side and carrying out primary dispersion on modulation detection light projected by an optical fiber array, the second lens group is used for controlling the telecentricity of the image side and carrying out secondary dispersion on the modulation detection light, and the long focal length of the first lens group is matched with the short focal length of the second lens group to be used for zooming control from the object side to the image side, wherein the object side/image side zooming magnification is f1/f2, f1 is the focal length of the first lens group, f2 is the focal length of the second lens group, the object side is the optical fiber array, and the image side is the line length projected by the dispersive objective lens;

the lens barrel comprises a first lens frame used for fixing the first lens group, a second lens frame used for fixing the second lens group and a lens base used for connecting the first lens frame and the second lens frame, and the first lens group and the second lens group are respectively fixed through the corresponding first lens frame and the second lens frame and then are matched through the lens base to realize the adjustment of focal length between the first lens group and the second lens group.

2. A dispersion lens according to claim 1, wherein: the inner walls of the first mirror frame and the second mirror frame are provided with black coating layers.

3. A dispersion lens according to claim 1, wherein: the first mirror frame and the mirror base are fixed in position through pin shafts and screws, and the mirror base and the second mirror frame are fixed in position through threaded connection.

4. A dispersion lens according to claim 1, wherein: the focal length of the first lens group is a long focal length, the first lens comprises a first lens, a second lens and a third lens which are coaxially arranged, wherein the first lens is used for compressing the aperture of a light beam of the modulation detection light and controlling object space telecentricity, and the second lens is used for balancing coma aberration, astigmatism and distortion of the modulation detection light and further compressing the light beam to generate partial dispersion; the third lens is used for eliminating field curvature and distortion of the modulation detection light, is matched with the first lens and is used for controlling object space telecentricity, and the focal length of the first lens group is controlled to be a long focal length.

5. The dispersing lens of claim 4 wherein the first lens is a positive long focal length lens with a focal length in the range of 200mm to 250mm, the second lens is a positive long focal length lens with a focal length in the range of 100mm to 150mm, and the third lens is a negative small focal length lens with a focal length in the range of-40 mm to 18 mm.

6. A dispersing lens according to claim 4 characterised in that the first lens is a positive meniscus lens, arranged towards the object, the second lens is a positive meniscus lens, arranged towards the object and the third lens is a negative meniscus lens, arranged towards the object.

7. A dispersion lens according to claim 1, wherein said second lens group includes a first lens unit, a second lens unit and a third lens unit which are coaxially arranged; the first lens unit is used for eliminating spherical aberration of the modulation detection light, controlling the focal length of the second lens group and controlling image space telecentricity; the second lens unit is used for balancing spherical aberration and coma aberration of the modulation detection light, compressing a beam divergence angle of the modulation detection light and further generating dispersion; the third lens unit is configured to remove residual spherical aberration, coma aberration, and astigmatism of the modulated detection light.

8. The dispersing lens of claim 7 wherein the first lens unit includes a fourth lens, the fourth lens is a negative mid-focal length lens, and the focal length ranges from-100 mm to-80 mm; the second lens unit comprises a fifth lens, a sixth lens and a seventh lens which are sequentially connected, wherein the fifth lens is a positive long focal length lens, the focal length range is 110 mm-160 mm, the sixth lens is a positive long focal length lens, the focal length range is 120 mm-170 mm, the seventh lens is a positive long focal length lens, and the focal length range is 150 mm-200 mm; the third lens unit includes an eighth lens and a ninth lens connected in series; the eighth lens is a positive long-focus lens, the focal length range is 160mm to 210mm, the ninth lens is a positive short-focus lens, and the focal length range is 30mm to 60 mm.

9. A dispersing lens according to claim 8, characterised in that the fourth lens is a biconcave lens; the fifth lens is a positive meniscus lens and is arranged towards the image space, the sixth lens is a double-convex lens, and the seventh lens is a positive meniscus lens and is arranged towards the object space; the eighth lens is a positive meniscus lens and is arranged towards the object space, and the ninth lens is a positive meniscus lens and is arranged towards the object space.

10. A dispersion lens according to claim 1, wherein: the zoom magnification of the object space and the image space is between 0.04 and 0.5;

and/or the length of the optical fiber array is 25mm-85 mm.