CN115685497A

CN115685497A - Dispersion lens

Info

Publication number: CN115685497A
Application number: CN202211385137.4A
Authority: CN
Inventors: 李文渊; 谢胜; 朱周德; 刘强生; 张腾飞
Original assignee: Shenzhen Daoxian Technology Co ltd
Current assignee: Shenzhen Daoxian Technology Co ltd
Priority date: 2022-11-07
Filing date: 2022-11-07
Publication date: 2023-02-03

Abstract

The application discloses dispersion lens includes: the light source comprises a first lens group, a light shielding component and a second lens group, wherein the first lens group is used for emitting incident light to the light shielding component, the light shielding component comprises a light shielding part and a light transmitting part, the light shielding part is used for shielding central light of the incident light, marginal light of the incident light is emitted to the second lens group through the light transmitting part, and the second lens group converges the marginal light to form measuring light spots corresponding to each wavelength in the marginal light one to one. The invention solves the technical problem of how to improve the precision of measuring a measured object with a tiny thickness under the condition of not changing the measuring range.

Description

Dispersion lens

Technical Field

The present application relates to the field of optical technology. More particularly, the present application relates to a dispersion lens.

Background

The dispersive lens is a special lens applied to a spectrum confocal sensor, is a core device of the spectrum confocal sensor, and determines parameters such as resolution, measuring range, line length and the like. The existing dispersion lens has the design difficulty that: most of conventional dispersion lenses are large-numerical-aperture lenses, and have spherical aberration influence, so that each wavelength light ray has a plurality of measurement light spots (also called focal points) in the depth direction of the lens in different numerical aperture angles, as shown in fig. 1, fig. 1 is a light path diagram of light rays with wavelengths of 460nm and 470nm, in fig. 1, the 460nm light ray generates two measurement light spots A1 and A2, and the 470nm light ray generates two measurement light spots B1 and B2, wherein B1 is located between A1 and A2 (that is, the measurement light spots with different wavelengths have a cross phenomenon), resulting in a peak value measured by two wavelengths as shown in fig. 2, that is, two peak values coincide. When the measured object with the small thickness is measured, an image mixing area can appear in the imaging process, so that the spectral confocal sensor cannot measure the measured object with the small thickness.

For the above defects, in the prior art, the signal-to-noise ratio is improved by a special objective lens under the condition of not reducing the range, so that the second peak value can be displayed, but the two peak values generated by the method still have higher overlap ratio, and the purpose of measuring the tiny thickness cannot be achieved.

Disclosure of Invention

It is an object of the present application to solve the above problems and to provide corresponding advantageous effects.

Another objective of the present application is to provide a chromatic dispersion lens, which solves the technical problem of how to improve the accuracy of measuring an object with a small thickness without changing the measurement range. The application is mainly realized by the following technical scheme:

the application provides a dispersion lens, including:

the light source comprises a first lens group, a light shielding component and a second lens group, wherein the first lens group is used for emitting incident light to the light shielding component, the light shielding component comprises a light shielding part and a light transmitting part, the light shielding part is used for shielding central light of the incident light, marginal light of the incident light is emitted to the second lens group through the light transmitting part, and the second lens group converges the marginal light to form measuring light spots corresponding to each wavelength in the marginal light one to one.

The beneficial effect of this application includes:

this application is through setting up the shading component that contains shading portion and printing opacity portion in dispersion lens for the central light of this application incident light is sheltered from by shading portion or is intercepted, and the marginal light of incident light (also be except that light of central light) can pass through printing opacity portion incides to second lens group, by second lens group assemble form with every wavelength one-to-one's measurement facula in the marginal light. That is, the light of every wavelength in the incident light, after the dispersion lens that this application provided assembles, all only assembles into a measurement facula, and two adjacent measurement facula have certain distance. Compared with the prior art in which light of each wavelength generates a plurality of measuring light spots and other wavelengths exist between two adjacent measuring light spots, when the measuring object with small thickness is measured, the imaging area of the measuring object can not be mixed, so that the phenomenon of crossing among the measuring light spots with different wavelengths can be effectively avoided, and the condition of peak value coincidence measured by two wavelengths can be further avoided. Therefore, the accuracy of measuring the measured object with the tiny thickness can be improved under the condition that the measuring range is not changed.

Because in a plurality of measurement facula that this application assembles, there is certain distance between two adjacent measurement facula for the resolution ratio of the image that forms through this application dispersion lens is higher than the resolution ratio of the image that traditional dispersion lens formed, and the formation of image is more clear.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments of the present application will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive exercise.

FIG. 1 is a diagram of a light path of a conventional dispersion lens for converging light;

FIG. 2 is a schematic diagram of a conventional spectral confocal sensor measuring the peak value of light emitted through a conventional dispersive lens;

FIG. 3 is a schematic diagram of the working principle of the spectral confocal sensor;

FIG. 4 is a schematic diagram of an optical path structure of a dispersion lens of the present application in some embodiments;

FIG. 5 is a diagram of an optical path of light converged by the dispersion lens of the present application;

FIG. 6 is a schematic view of the shading member of the present application in some embodiments;

description of the reference numerals: 1. a dispersion lens; 10. a first lens group; 11. a first lens; 12. a second lens; 20. a light shielding member; 21. a light shielding portion; 22. a light-transmitting portion; 30. a second lens group; 31. a third lens; 32. and a fourth lens.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application more clearly and completely apparent, the technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The terms "first" and "second" and the like in the description of the embodiments of the present application are used for distinguishing different objects, and are not used for describing a specific order of the objects. For example, the first lens group and the second lens group are for distinguishing different lens groups, rather than for describing a particular order of the lens groups.

In the embodiments of the present application, words such as "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.

Explanation of working principle of spectral confocal sensor:

as shown in fig. 3, the light source is emitted from the S-aperture, and is focused by the dispersion objective lens to generate spectral dispersion, so as to form monochromatic light focuses continuously distributed along different wavelengths in the optical axis direction on the image plane, and the distances from the monochromatic light focus of each wavelength to the object to be measured are different. When the measured object is at a certain position in the measuring range, only light with specific wavelength is in a focusing state on the measured surface, the light with the wavelength can be reflected from the surface of the measured object and enter the spectrometer because the light meets the confocal condition, and light with other wavelengths is in a defocusing state on the surface of the measured object and cannot enter the spectrometer after being reflected. And decoding by the spectrometer to obtain the wavelength value of the maximum echo light intensity, thereby measuring the distance value corresponding to the measured object.

The following further describes embodiments of the present application with reference to the drawings.

As shown in fig. 4, a dispersion lens 1 according to an embodiment of the present application is provided. In fig. 4, the dispersive lens 1 includes a first lens group 10, a light shielding member 20, and a second lens group 30, wherein the first lens group 10 is configured to emit incident light to the light shielding member 20, the light shielding member 20 includes a light shielding portion 21 and a light transmitting portion 22, as shown in fig. 6, the light shielding portion 21 is configured to shield a central light of the incident light, an edge light of the incident light is emitted to the second lens group 30 through the light transmitting portion 22, and the second lens group 30 converges the edge light to form measurement spots corresponding to each wavelength of the edge light one to one.

As shown in fig. 5, fig. 5 is a light path diagram of light rays with wavelengths of 460nm and 470nm converged by the dispersion lens 1, the light rays with the wavelength of 460nm are converged into only one measurement spot C, the light rays with the wavelength of 470nm are also converged into only one measurement spot D, and imaging areas with two wavelengths have a certain distance, so that the phenomenon of overlapping does not occur. Therefore, the resolution ratio of the imaging of the measured object can be improved, and the accuracy of measuring the measured object with the small thickness is improved.

It should be understood that the dispersive lens 1 provided in the embodiments of the present application is applied to a point spectrum confocal sensor.

The size of the Airy spot radius of the edge ray is not changed because the central ray is shielded by the shielding part.

The first lens group 10 is for enabling light of a large angle to entirely enter the light shielding member 20; the second lens group 30 is used for dispersing different light to different depth positions, i.e., for converging light of different wavelengths.

In some embodiments, the first lens group 10 includes a first lens 11 and a second lens 12.

The incident surface curvature radius of the first lens 11 is set to 172.64mm, the thickness is set to 2.8mm, the material is H-ZF88, and the half diameter is set to 4.11mm.

The radius of curvature of the exit surface of the first lens 11 is set to-15.66 mm, the thickness is set to 0.33mm, and the half diameter is set to 4.30mm.

The radius of curvature of the entrance surface of the second lens 12 is set to-12.87 mm, the thickness is set to 2mm, the material is H-ZF88, and the half diameter is set to 4.28mm.

The radius of curvature of the exit surface of the second lens 12 was set to-19.31 mm, the thickness was set to 0.20mm, and the half diameter was set to 4.54mm.

In this embodiment, the first lens 11 is a double cemented lens, and the second lens 12 is a ziming lens. The double cemented lens and the aplanatic lens can effectively reduce the spherical aberration, even reduce the spherical aberration to zero.

In some embodiments, the light shielding member 20 is a diaphragm.

In some embodiments, the light shielding portion 21 has a black coating. Specifically, the blackout layer covers the entire light shielding portion 21.

In some embodiments, the second lens group 30 includes a third lens 31 and a fourth lens 32.

The third lens 31 has an entrance surface curvature radius of 19.31mm, a thickness of 2mm, a material H-ZF88, and a half diameter of 4.54mm.

The radius of curvature of the exit surface of the third lens 31 is set to 12.87mm, the thickness is set to 0.33mm, and the half diameter is set to 4.28mm.

The fourth lens 32 has an entrance surface curvature radius set to 15.66mm, a thickness set to 2.80mm, a material H-ZF88, and a half diameter set to 4.30mm.

The exit surface radius of curvature of the fourth lens 32 was set to-172.64 mm, the thickness was set to 15.15mm, and the half diameter was set to 4.11mm.

The third lens 31 is a aplanatic lens, and the fourth lens 32 is a double cemented lens.

In some embodiments, the dispersive lens 1 further comprises a lens barrel for fixing the first lens group 10, the light shielding member 20 and the second lens group 30.

The present application and its embodiments are described above, the description is not limited, and what is shown in the drawings is only one of the embodiments of the present application, and the actual structure is not limited thereto. In summary, those skilled in the art should be able to conceive of the invention that any similar structural modes and embodiments to those described above should be covered by the protection scope of the embodiments of the present application without creative design and without departing from the spirit of the embodiments of the present application.

Claims

1. A dispersion lens, comprising:

2. The dispersing lens of claim 1, wherein the first lens group includes a first lens and a second lens.

3. The dispersing lens of claim 2 wherein the first lens is a doublet and the second lens is a ziming lens.

4. The dispersion lens according to claim 3, wherein the light shielding member is a diaphragm.

5. The dispersion lens according to claim 3, wherein the light shielding portion has a black coating layer.

6. A dispersing lens according to any one of claims 4 or 5, characterised in that the second lens group comprises a third lens and a fourth lens.

7. The dispersing lens of claim 6, wherein the third lens is a ziming lens and the fourth lens is a doublet.

8. The dispersion lens of claim 7, further comprising a lens barrel for fixing the first lens group, the light-shielding member, and the second lens group.