Line spectrum confocal sensor

Abstract

The embodiment of the invention discloses a line spectrum confocal sensor, which comprises a light source system, and the light source system comprises at least one light source assembly which is linearly arranged and is used for providing a first light beam transmitted along multiple directions; the first cylindrical lens assembly is used for receiving the first light beam and carrying out collimation processing on the first light beam to obtain a parallel second light beam transmitted along the same direction; the second cylindrical lens assembly is used for receiving the second light beam and focusing the second light beam to obtain a third light beam transmitted in multiple directions; the third cylindrical lens assembly is used for receiving the third light beam and collimating the third light beam to obtain a fourth light beam transmitted along the same direction; the width of the fourth light beam is smaller than that of the second light beam received by the second cylindrical lens assembly, and the width of the fourth light beam is determined by the beam shrinkage ratio between the second cylindrical lens assembly and the third cylindrical lens assembly.

Description

Technical Field

[0001] The present application relates to the technical field of spectral confocal distance measurement, and in particular to a line spectral confocal sensor. Background Art

[0002] Spectral confocal sensor is an advanced optical sensing technology, which uses the optical confocal principle and spectral analysis technology to detect the distance of the sample. With the development needs, the current spectral confocal sensor has a large transmission light beam loss and low utilization rate. Summary of the invention

[0003] The embodiment of the present application provides a line spectrum confocal sensor, including: a light source system, wherein; the light source system includes:

[0004] At least one light source assembly, the at least one light source assembly is arranged linearly and is used to provide a first light beam transmitted in multiple directions;

[0005] A first cylindrical lens assembly, used for receiving the first light beam and performing collimation processing on the first light beam to obtain a parallel second light beam transmitted in the same direction;

[0006] a second cylindrical lens assembly, used for receiving the second light beam and focusing the second light beam to obtain a third light beam transmitted in multiple directions;

[0007] The third cylindrical lens assembly is used to receive the third light beam and collimate the third light beam to obtain a fourth light beam transmitted in the same direction; the width of the fourth light beam is smaller than the second light beam received by the second cylindrical lens assembly and the width of the fourth light beam is determined by the beam reduction ratio between the second cylindrical lens assembly and the third cylindrical lens assembly.

[0008] In the above solution, the light source system further includes: a first slit; and the width of the fourth light beam is determined by the width of the first slit.

[0009] In the above solution, the reduction ratio is a ratio between a first focal length of the second cylindrical lens assembly and a second focal length of the third cylindrical lens assembly.

[0010] In the above solution, the first focal length of the second cylindrical lens assembly and the second focal length of the third cylindrical lens assembly are selected according to the width of the first slit.

[0011] In the above solution, the width of the first slit is equal to the arrangement length of the at least one light source assembly.

[0012] In the above scheme, it also includes: a spectroscopic system; wherein the spectroscopic system includes: a polarization spectroscopic prism PBS and a glass slide, wherein;

[0013] The PBS is used to receive the fourth light beam passing through the first slit, and split the fourth light beam into a first sub-beam and a second sub-beam, wherein the first sub-beam is P-polarized light; and the second sub-beam is S-polarized light;

[0014] The glass slide, whose fast axis or slow axis forms an angle of 45 degrees with the optical axis of the PBS, is used to receive the reflected light beam and rotate the polarization direction of the reflected light beam so that the reflected light beam is completely incident on the spectrometer system included in the line spectrum confocal sensor through the PBS; the reflected light beam is the light beam reflected by the first sub-beam through the dispersion system included in the line spectrum confocal sensor and the object to be measured.

[0015] In the above scheme, a second slit is also included;

[0016] The dispersion system is used to receive the first sub-beam, focus the lights of different wavelengths respectively after axially dispersing the first sub-beam, and conduct the reflected light beam reflected by the measured object;

[0017] The second slit is used to filter the reflected light beam;

[0018] The spectrometer system is used to receive the reflected light beam after filtering, focus the reflected light beam onto the photosensitive subsystem included in the spectrometer system, and quantify it into a spectrum curve.

[0019] In the above solution, the light source assembly includes an LED light source.

[0020] In the above scheme, the photosensitive subsystem includes: a photosensitive coupling component CCD.

[0021] In the above scheme, the dispersion system includes: a dispersion focusing lens, which is used to receive the first sub-beam, axially disperse the first sub-beam and focus it separately, wherein the monochromatic beam focused on the surface of the measured object becomes the reflected beam after being reflected.

[0022] The embodiment of the present application provides a line spectrum confocal sensor. The line spectrum confocal sensor includes: a light source system, the light source system includes: at least one light source component, the at least one light source component is arranged linearly and is used to provide a first light beam transmitted in multiple directions; a first cylindrical lens component is used to receive the first light beam and collimate the first light beam to obtain a parallel second light beam transmitted in the same direction; a second cylindrical lens component is used to receive the second light beam and focus the second light beam to obtain a third light beam transmitted in multiple directions; a third cylindrical lens component is used to receive the third light beam and collimate the third light beam to obtain a fourth light beam transmitted in the same direction; the width of the fourth light beam is smaller than the second light beam received by the second cylindrical lens component and the width of the fourth light beam is determined by the beam reduction ratio between the second cylindrical lens component and the third cylindrical lens component. The line spectrum confocal sensor provided in the embodiment of the present application converts the light beam emitted by the light source into a parallel light beam whose width is determined by the beam reduction ratio by arranging the light source components linearly and using three groups of cylindrical lenses, so that all or most of the light beam emitted by the light source is applied to the optical device described later, so as to achieve the purpose of improving the utilization rate of the light beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In the drawings, which are not necessarily drawn to scale, the same reference numerals may describe similar components in different views. The same numerals with different letter suffixes may represent different instances of similar components. The drawings generally illustrate various embodiments discussed in this document by way of example and not limitation.

[0024] Figure 1 A schematic diagram of the structure of a spectral confocal sensor provided in an embodiment of the present application;

[0025] Figure 2 A schematic diagram of the structure of a light source system provided in an embodiment of the present application;

[0026] Figure 3 A schematic diagram of the structure of a PBS included in the optical splitting system provided in an embodiment of the present application;

[0027] Figure 4 A schematic diagram of the propagation of the light beam line of the light splitting system provided in an embodiment of the present application;

[0028] Among them, 100-line spectrum confocal sensor; 10-light source system; 20-spectrometric system; 30-dispersion system; 40-spectrometer system; 50-measured object; 101-LED light source; 102-first cylindrical lens assembly; 103-second cylindrical lens assembly; 104-third cylindrical lens assembly; 105-first slit; 201-PBS; 202-1 / 4 glass slide. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the specific technical solution of the present application will be further described in detail below in conjunction with the drawings in the embodiments of the present application. The following embodiments are used to illustrate the present application, but are not used to limit the scope of the present application.

[0030] In the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implying the number of technical features indicated by the term. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the feature. In the description of the embodiments of the present application, unless otherwise specified, "multiple" means two or more.

[0031] In addition, in the embodiments of the present application, directional terms such as "up", "down", "left" and "right" are defined relative to the orientation of the components in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they may change accordingly according to changes in the orientation of the components in the drawings.

[0032] In the embodiments of the present application, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes the elements in a step-by-step manner, and also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0033] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or related scheme described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0034] See also Figure 1 , which shows a schematic diagram of the structure of a line spectrum confocal sensor provided in an embodiment of the present application. Figure 1 As shown, the line spectrum confocal sensor 100 includes: a light source system 10, wherein; the light source system 10 may include:

[0035] At least one light source assembly 101, wherein the at least one light source assembly is arranged linearly and is used to provide a first light beam transmitted in multiple directions;

[0036] A first cylindrical lens assembly 102, used for receiving the first light beam and performing collimation processing on the first light beam to obtain a parallel second light beam transmitted in the same direction;

[0037] A second cylindrical lens assembly 103 is used to receive the second light beam and focus the second light beam to obtain a third light beam transmitted in multiple directions;

[0038] The third cylindrical lens assembly 104 is used to receive the third light beam and collimate the third light beam to obtain a fourth light beam transmitted in the same direction; the width of the fourth light beam is smaller than the second light beam received by the second cylindrical lens assembly and the width of the fourth light beam is determined by the beam reduction ratio between the second cylindrical lens assembly and the third cylindrical lens assembly.

[0039] It should be noted that, here, the light source assembly can be an LED light source. In the spectral confocal sensor, the first slit can be in the shape of a long strip, therefore, the at least one light source assembly can be arranged linearly (that is, in one dimension), and the width of the first slit is equal to the arrangement length of the at least one light source assembly. In other words, the first slit is in the shape of a long strip, therefore, the light source assembly is arranged in one dimension so that the width of the first slit matches the arrangement length of the light source assembly. Specifically, the arrangement of the at least one light source assembly, for example, can be seen in Figure 2 shown.

[0040] like Figure 2 As shown, the at least one light source assembly is arranged in one dimension along the vertical direction, so that the first light beam is divergent along the vertical direction.

[0041] like Figure 2As shown, the cylindrical surfaces of the first cylindrical lens assembly 102, the second cylindrical lens assembly 103, and the third cylindrical lens assembly 104 are parallel to the length direction of the first slit, that is, the cylindrical surfaces of the first cylindrical lens assembly 102, the second cylindrical lens assembly 103, and the third cylindrical lens assembly 104 are perpendicular to the propagation direction of the parallel second light beam. The first cylindrical lens assembly 102 may be a cylindrical lens with a vertical curvature, which is used to collimate the first light beam. Specifically, the first light beam diverges in the vertical direction. After passing through the first cylindrical lens assembly 102, the cylindrical lens with a vertical curvature can be used to focus the first light beam to make it a parallel light beam, that is, to form a second light beam. The second cylindrical lens assembly 103 may include a positive cylindrical lens, which has a positive focal length and can focus parallel light rays into a line. In the embodiment of the present application, the second cylindrical lens assembly 103 is incident with all or part of the parallel second light beam, and focuses the second light beam to form a focused (i.e., multi-directionally transmitted) third light beam. The third cylindrical lens assembly 104 can also be a group of collimating lenses, which are used to collimate the third light beam to form a parallel fourth light beam.

[0042] It should be noted that Figure 2 The light source system shown is only an example for explaining the implementation principle. The light source system is applied to a spectral confocal sensor, the internal space of which is limited, and the layout is determined according to the actual situation.

[0043] In some embodiments, the light source system 10 may further include: a first slit; and the width of the fourth light beam is determined by the width of the first slit.

[0044] It should be noted that the light beam emitted by the LED light source is collimated by the first cylindrical lens assembly, and then is reduced by the second cylindrical lens assembly and the third cylindrical lens assembly, so that the light beam is reduced to match the first slit, so that the light source can be fully utilized. That is, in the spectral confocal sensor, the width of the first slit is certain. In order to make the light beam emitted by the light source fully utilized, the second cylindrical lens assembly and the third cylindrical lens assembly are used to reduce the beam, and finally the width of the reduced beam is matched with the width of the first slit. That is, the second cylindrical lens assembly and the third cylindrical lens assembly are set to make the light beam match the width of the first slit, that is, the selection of the second cylindrical lens assembly and the third cylindrical lens assembly is determined by the width of the first slit.

[0045] More specifically, the reduction ratio may be a ratio between a first focal length F1 of the second cylindrical lens assembly and a second focal length F2 of the third cylindrical lens assembly, that is, F1 / F2. The first focal length of the second cylindrical lens assembly and the second focal length of the third cylindrical lens assembly are selected according to the width of the first slit.

[0046] In some embodiments, the line spectrum confocal sensor 100 may further include: a light splitting system 20; wherein the light splitting system 20 may include: a polarizing beam splitter prism (PBS, Polarizing Beam Splitter) 201 and a glass slide 202, wherein;

[0047] The PBS 201 is used to receive the fourth light beam passing through the first slit 105, and split the fourth light beam into a first sub-beam and a second sub-beam, wherein the first sub-beam is P-polarized light; and the second sub-beam is S-polarized light;

[0048] The glass slide 202, whose fast axis or slow axis forms an angle of 45 degrees with the optical axis of the PBS, is used to receive the reflected light beam and rotate the polarization direction of the reflected light beam so that the reflected light beam is completely incident on the spectrometer system 40 included in the line spectrum confocal sensor through the PBS; the reflected light beam is the light beam reflected by the first sub-beam through the dispersion system 30 included in the line spectrum confocal sensor and the object to be measured 50.

[0049] It should be noted that the PBS can be a special optical element that uses the polarization characteristics of light to separate or merge light beams of different polarization directions. This prism can include two or more prisms, which are precisely aligned to achieve polarized light splitting or light combination. The working principle of the PBS can be as follows: polarization selectivity, only allowing light of a specific polarization direction to pass through. For example, the PBS can include a cube shape, and one of the faces is coated with a special film, which can reflect light of one polarization direction and transmit light of another polarization direction. The glass slide (or wave plate) can be a 1 / 4 wave plate, which can also be called a quarter glass slide or a quarter wavelength plate, which is a special polarization optical element used to change the polarization state of light passing through it. The thickness of this glass slide is designed so that when light propagates therein, the phase delay is exactly one quarter of the wavelength of the light. The 1 / 4 wave plate includes two main axes, a fast axis and a slow axis, wherein the fast axis can be a direction with a lower refractive index, and the slow axis can be a direction with a higher refractive index, and the light waves passing through these two axes will have different phase velocities.

[0050] like Figure 3 As shown, it shows a schematic diagram of the optical structure of the PBS included in the spectroscopic system of the spectral confocal sensor provided in the embodiment of the present application. Figure 3In the embodiment, the PBS included in the light splitting system may include two triangular PBS prisms, with a 50:50 light splitting film coated on the inclined surface. Figure 3 The PBS shown contains a spectroscopic system, such as Figure 4 As shown, it shows a schematic diagram of the propagation of the optical line. Specifically, the light beam 1 (i.e., the fourth light beam, with 100% energy) emitted by the LED light source becomes polarized light after passing through the PBS, and the light at this time becomes linearly polarized light: P polarized light beam 2 (i.e., the first sub-beam), S polarized light beam 3 (i.e., the second sub-beam), wherein the P polarized light beam 2 passes through the 1 / 4 wave plate and the light beam 4 emitted back by the dispersion system 30; the light beam 4 passes through the 1 / 4 wave plate and enters the spectrometer system 40. At this time, it is ensured that the angle between the 1 / 4 wave plate and the optical axis of the spectrometer system is 45 degrees, then the polarization direction of the light beam 4 (i.e., the reflected light beam) reflected back by the dispersion system 30 is rotated by 90 degrees, and the reflected light beam just passes through the PBS and enters the spectrometer system 40, so that no energy loss will be caused. The S polarized light beam 3 is lost, and its energy is 50%. That is to say, the spectrometer system provided in the embodiment of the present application only loses 50% of its energy when the light beam 1 emitted from the light source enters the PBS, and there will be no more energy loss in the subsequent light beam propagation process.

[0051] In some embodiments, the line spectrum confocal sensor 100 may further include a second slit;

[0052] The dispersion system 30 is used to receive the first sub-beam, and focus the lights of different wavelengths respectively after axially dispersing the first sub-beam, and transmit the reflected light beam reflected by the measured object;

[0053] The second slit is used to filter the reflected light beam;

[0054] The spectrometer system 40 is used to receive the reflected light beam after filtering, focus the reflected light beam onto the photosensitive subsystem included in the spectrometer system, and quantify it into a spectrum curve.

[0055] It should be noted that the second slit is located between the spectroscopic system 20 and the spectrometer system 40, and is used to receive the reflected light beam transmitted from the spectroscopic system 20, and filter the reflected light beam to limit only light of a specific wavelength to enter the spectrometer system, thereby obtaining more accurate spectral data. Here, the dispersion system 30 mainly has two functions: first, receiving the first sub-beam, and focusing the light of different wavelengths respectively after axial dispersion of the first sub-beam; second, conducting the reflected light beam emitted by the object to be measured, wherein the reflected light beam can be the light beam after the monochromatic light beam focused on the surface of the object to be measured in the first sub-beam is reflected. Here, the spectrometer system 40 can receive the reflected light beam after filtering by the second slit, and then focus the reflected light beam on the photosensitive subsystem included in the spectrometer system 40 and quantify the reflected light beam into a spectral curve. The spectrometer system establishes a corresponding relationship between the wavelength, the displacement of the object to be measured, and the peak position of the spectral curve, and then analyzes it, and infers the displacement of the object to be measured through the peak of the spectral curve, thereby realizing the process of measuring the displacement using the spectral confocal principle.

[0056] In some embodiments, the photosensitive subsystem may include: a charge coupled device (CCD). Here, CCD may be a photoelectric sensor widely used in digital imaging and data storage, which captures images by converting optical signals into electrical signals.

[0057] In some embodiments, the dispersion system 30 may include: a dispersion focusing lens, used to receive the first sub-beam, axially disperse the first sub-beam and focus it separately, wherein the monochromatic beam focused on the surface of the object to be measured becomes the reflected beam after being reflected.

[0058] It should be noted that the dispersion focusing lens can be a special type of lens, which uses the difference in refractive index of light of different wavelengths in the medium to achieve focusing. This characteristic of the refractive index changing with wavelength is called dispersion, which is used to achieve separation and focusing of light of different wavelengths. Here, the monochromatic light beam can refer to a single-wavelength light beam, that is, the light in the light beam belongs to the same wavelength.

[0059] The line spectrum confocal sensor provided in the embodiment of the present application adds three groups of one-dimensional cylindrical lenses in front of the light source LED, which can achieve the stretching and contraction of the light source in one-dimensional direction, and enter the slit and subsequent optical system in a form matching the slit width, thereby greatly improving the energy utilization of the light source and reducing energy loss. In addition, the use of PBS and combined with a 1 / 4 wave plate can further improve the utilization rate.

[0060] It should be noted that the "first", "second", etc. that appear in this application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. In addition, in the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored, or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0061] The above description is only a preferred embodiment of the present application and is not intended to limit the protection scope of the present application.

Claims

1. A line spectrum confocal sensor, characterized in that: include: A light source system, wherein; The light source system comprises: At least one light source assembly, the at least one light source assembly is arranged linearly and is used to provide a first light beam transmitted in multiple directions; A first cylindrical lens assembly, used for receiving the first light beam and performing collimation processing on the first light beam to obtain a parallel second light beam transmitted in the same direction; a second cylindrical lens assembly, used for receiving the second light beam and focusing the second light beam to obtain a third light beam transmitted in multiple directions; The third cylindrical lens assembly is used to receive the third light beam and collimate the third light beam to obtain a fourth light beam transmitted in the same direction; the width of the fourth light beam is smaller than the second light beam received by the second cylindrical lens assembly and the width of the fourth light beam is determined by the beam reduction ratio between the second cylindrical lens assembly and the third cylindrical lens assembly.

2. The line spectrum confocal sensor according to claim 1, characterized in that: The light source system further includes: a first slit; and the width of the fourth light beam is determined by the width of the first slit.

3. The line spectrum confocal sensor according to claim 2, characterized in that: The attenuation ratio is a ratio between a first focal length of the second cylindrical lens assembly and a second focal length of the third cylindrical lens assembly.

4. The line spectrum confocal sensor according to claim 3, characterized in that: The first focal length of the second cylindrical lens assembly and the second focal length of the third cylindrical lens assembly are selected according to the width of the first slit.

5. The line spectrum confocal sensor according to claim 2, characterized in that: The width of the first slit is equal to the arrangement length of the at least one light source assembly.

6. The line spectrum confocal sensor according to claim 2, characterized in that: Also includes: Spectroscopic system; wherein, the spectroscopic system comprises: a polarization spectroscopic prism PBS and a glass slide, wherein; The PBS is used to receive the fourth light beam passing through the first slit, and split the fourth light beam into a first sub-beam and a second sub-beam, wherein the first sub-beam is P-polarized light; and the second sub-beam is S-polarized light; The glass slide, whose fast axis or slow axis forms an angle of 45 degrees with the optical axis of the PBS, is used to receive the reflected light beam and rotate the polarization direction of the reflected light beam so that the reflected light beam is completely incident on the spectrometer system included in the line spectrum confocal sensor through the PBS; the reflected light beam is the light beam reflected by the first sub-beam through the dispersion system included in the line spectrum confocal sensor and the object to be measured.

7. The line spectrum confocal sensor according to claim 6, characterized in that: Also comprising a second slit; The dispersion system is used to receive the first sub-beam, focus the lights of different wavelengths respectively after axially dispersing the first sub-beam, and conduct the reflected light beam reflected by the measured object; The second slit is used to filter the reflected light beam; The spectrometer system is used to receive the reflected light beam after filtering, focus the reflected light beam onto the photosensitive subsystem included in the spectrometer system, and quantify it into a spectrum curve.

8. The line spectrum confocal sensor according to claim 1, characterized in that: The light source assembly includes an LED light source.

9. The line spectrum confocal sensor according to claim 7, characterized in that: The photosensitive subsystem includes: a photosensitive coupling component CCD.

10. The line spectrum confocal sensor according to claim 7, characterized in that: The dispersion system includes: a dispersion focusing lens, which is used to receive the first sub-beam, axially disperse the first sub-beam and focus the first sub-beam, wherein the monochromatic beam focused on the surface of the measured object becomes the reflected beam after being reflected.

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