Light path system for reducing near infrared spectrum base line inclination condition

Abstract

The invention relates to a near-infrared spectrometer, in particular to an optical path system for reducing the inclination condition of a near-infrared spectrum baseline, which comprises a first optical fiber, a second optical fiber, a first off-axis parabolic mirror, a second off-axis parabolic mirror, a plurality of reflectors and a body, the first off-axis parabolic mirror is used for reflecting the optical fiber emitted by the first optical fiber to the reflector, the optical fiber is reflected to the second off-axis parabolic mirror again through the reflector, and finally the optical fiber is reflected by the second off-axis parabolic mirror to the second optical fiber to be gathered. A first sliding groove and a second sliding groove are formed in the two ends of the body and used for allowing the first off-axis parabolic mirror and the second off-axis parabolic mirror to slide so as to adjust an optical path, and a plurality of reflectors are further arranged between the body so that the first optical fiber can be communicated with the second optical fiber. By means of the structure, the optical path can be conveniently adjusted through the movable sliding groove, and meanwhile the position of the optical fiber is easier to organize by means of intervention of the reflecting mirror.

Description

Technical Field

[0001] The invention relates to a near-infrared spectrometer, in particular to an optical path system for reducing the inclination of a near-infrared spectrum baseline. Background Art

[0002] The description in this section merely provides background information related to the present disclosure and does not constitute prior art.

[0003] Current near-infrared devices generally use a transmissive optical path. At the same time, during the use of the near-infrared spectrometer, the optical fiber usually needs to be plugged and unplugged multiple times, or the host needs to be modeled offline. Therefore, the original optical path state may be changed, and further cause the lens dispersion at the tolerance-sensitive position near the optical path plug-in position to cause the baseline to tilt, affecting the measurement of the near-infrared spectrum.

[0004] Therefore, some existing near-infrared spectrometers consider using off-axis reflective optical path intervention to eliminate the influence of dispersion. However, due to the large size of the axial parabolic mirror, the complex adjustment of the optical path and the higher precision requirements, it is not convenient to make quick adjustments, which seriously affects the measurement efficiency. Alternatively, the layout of the optical path is unreasonable, resulting in a limited insertion angle of the optical fiber, which also affects the convenience of measurement.

[0005] Currently, there is no optical path system that can reduce the baseline tilt of near-infrared spectra and solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to provide an optical path system for reducing the baseline tilt of the near-infrared spectrum. The optical path can be conveniently adjusted through a movable slide, and the position of the optical fiber can be more easily organized through the intervention of a reflector.

[0007] In order to achieve the above object, the present invention discloses the following optical path system for reducing the inclination of the near-infrared spectrum baseline; the optical path system for reducing the inclination of the near-infrared spectrum baseline comprises:

[0008] A first optical fiber, a second optical fiber, a first off-axis parabolic mirror, a second off-axis parabolic mirror, a plurality of reflectors and a body;

[0009] The free end of the first optical fiber is aligned with the focus of the first off-axis parabolic mirror, a first connecting line is formed between the first single-core optical fiber and the focus of the first off-axis parabolic mirror, a second connecting line is formed between the focus of the first off-axis parabolic mirror and one of the corresponding reflectors, and an angle formed between the first connecting line and the second connecting line is the same as the off-axis angle of the first off-axis parabolic mirror;

[0010] The free end of the second optical fiber is aligned with the focus of the second off-axis parabolic mirror, a third connecting line is formed between the second single-core optical fiber and the focus of the second off-axis parabolic mirror, a fourth connecting line is formed between the focus of the second off-axis parabolic mirror and one of the corresponding reflectors, and an angle formed between the second connecting line and the fourth connecting line is the same as the off-axis angle of the second off-axis parabolic mirror;

[0011] Wherein, a first slide groove and a second slide groove are provided at both ends of the body, the first off-axis parabolic mirror is installed in the first slide groove, and the first off-axis parabolic mirror can move forward and backward in the first slide groove, the second off-axis parabolic mirror is installed in the second slide groove, and the second off-axis parabolic mirror can move forward and backward in the second slide groove, and by moving the first off-axis parabolic mirror and the second off-axis parabolic mirror, the light beam emitted from the free end of the first optical fiber and passing through the first connecting line passes through the third connecting line after being reflected by the first off-axis parabolic mirror, the second off-axis parabolic mirror, and multiple reflectors and is gathered by the free end of the second optical fiber.

[0012] Furthermore, the number of the reflectors is two, and the two reflectors are arranged parallel to each other, so that the first connecting line and the third connecting line are parallel, the second connecting line and the fourth connecting line are parallel, the second connecting line and the fourth connecting line are connected to have a fifth connecting line, and the fifth connecting line passes through the center position of the area to be detected of the main body.

[0013] Furthermore, a first concave screw hole is provided on a surface of the first off-axis parabolic mirror facing the outer side of the main body. When the first off-axis parabolic mirror moves to a preset position in the first slide groove, a first baffle plate whose size is larger than the aperture of the first slide groove is covered on the outside of the first slide groove, and the first fastener is passed through the first baffle plate and fixed in the first screw hole, so that the first off-axis parabolic mirror is fixed; a second concave screw hole is provided on a surface of the second off-axis parabolic mirror facing the outer side of the main body. When the second off-axis parabolic mirror moves to a preset position in the second slide groove, a second baffle plate whose size is larger than the aperture of the second slide groove is covered on the outside of the second slide groove, and the second fastener is passed through the second baffle plate and fixed in the second screw hole, so that the second off-axis parabolic mirror is fixed.

[0014] Furthermore, the first off-axis parabolic mirror is fixed in the first slide groove by gluing; and the second off-axis parabolic mirror is fixed in the second slide groove by gluing.

[0015] Furthermore, the first off-axis parabolic mirror and the second off-axis parabolic mirror are configured to be identical.

[0016] Furthermore, the first off-axis parabolic mirror and the second off-axis parabolic mirror are 90-degree off-axis parabolic mirrors.

[0017] Furthermore, the main body includes a plurality of mounting grooves, and the plurality of reflectors are detachably mounted in the corresponding mounting grooves.

[0018] Furthermore, the main body includes a first slot and a second slot, the first slot is arranged adjacent to the first off-axis parabolic mirror, and the first optical fiber is detachably inserted in the first slot; the second slot is arranged adjacent to the second off-axis parabolic mirror, and the second optical fiber is detachably inserted in the second slot.

[0019] By means of the above technical solution, the beneficial effects of the present invention are as follows:

[0020] The optical path system for reducing the baseline tilt of the near-infrared spectrum of the present invention can, when installed, set a corresponding number and angle of reflectors 5 according to the position and angle requirements of the first optical fiber 1 and the second optical fiber 2 in the actual optical path, and install them in the corresponding prefabricated body 6, so that during actual use, the position of the first optical fiber 1 and the second optical fiber 2 inserted into the body 6 is in a state that meets the needs of convenient operation.

[0021] To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and description and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0023] Figure 1 It is a cross-sectional schematic diagram of an optical path system for reducing the baseline tilt of a near-infrared spectrum provided in an embodiment of this specification;

[0024] Figure 2 It is a three-dimensional schematic diagram of an optical path system for reducing the baseline tilt of a near-infrared spectrum provided in an embodiment of this specification;

[0025] Figure 3 This is a schematic diagram of a lens transmission light path of an optical path system for reducing the baseline tilt of a near-infrared spectrum provided in an embodiment of this specification;

[0026] Figure 4This is a schematic diagram of an off-axis reflective optical path of an optical path system for reducing the baseline tilt of a near-infrared spectrum provided in an embodiment of this specification;

[0027] Figure 5 It is a schematic diagram of an embodiment of fermented grains detection of an optical path system for reducing the baseline tilt of a near-infrared spectrum provided in an embodiment of this specification;

[0028] In the figure: 1. first optical fiber; 2. second optical fiber; 3. first off-axis parabolic mirror; 31. first screw hole; 4. second off-axis parabolic mirror; 32. second screw hole; 5. reflecting mirror; 6. main body; 61. first slide groove; 62. second slide groove; 71. first connecting line; 72. second connecting line; 73. third connecting line; 74. fourth connecting line; 75. fifth connecting line. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this specification.

[0030] The following is an explanation of the embodiments of the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted according to actual sizes. It is stated in advance. The following embodiments will further explain the relevant technical contents of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention.

[0031] It should be understood that, although the terms "first", "second", "third", etc. may be used herein to describe various components or signals, these components or signals should not be limited by these terms. These terms are mainly used to distinguish one component from another component, or one signal from another signal. In addition, the term "or" used herein may include any one or more combinations of the associated listed items depending on the actual situation.

[0032] See also Figure 1-2 , is an optical path system for reducing the near-infrared spectrum baseline tilt of this embodiment; wherein the optical path system for reducing the near-infrared spectrum baseline tilt includes:

[0033] A first optical fiber 1, a second optical fiber 2, a first off-axis parabolic mirror 3, a second off-axis parabolic mirror 4, a plurality of reflectors 5 and a body 6;

[0034] The free end of the first optical fiber 1 is aligned with the focus of the first off-axis parabolic mirror 3, a first connecting line 71 is formed between the first single-core optical fiber 1 and the focus of the first off-axis parabolic mirror 3, a second connecting line 72 is formed between the focus of the first off-axis parabolic mirror 3 and one of the corresponding reflectors 5, and an angle formed between the first connecting line 71 and the second connecting line 72 is the same as the off-axis angle of the first off-axis parabolic mirror 3;

[0035] The free end of the second optical fiber 2 is aligned with the focus of the second off-axis parabolic mirror 4, a third connecting line 73 is formed between the second single-core optical fiber 2 and the focus of the second off-axis parabolic mirror 4, a fourth connecting line 74 is formed between the focus of the second off-axis parabolic mirror 4 and one of the corresponding reflectors 5, and an angle formed between the second connecting line 72 and the fourth connecting line 74 is the same as the off-axis angle of the second off-axis parabolic mirror 4;

[0036] Among them, a first slide groove 61 and a second slide groove 62 are provided at both ends of the body 6, the first off-axis parabolic mirror 3 is installed in the first slide groove 61, and the first off-axis parabolic mirror 3 can move forward and backward in the first slide groove 61, the second off-axis parabolic mirror 4 is installed in the second slide groove 62, and the second off-axis parabolic mirror 4 can move forward and backward in the second slide groove 62, by moving the first off-axis parabolic mirror 61 and the second off-axis parabolic mirror 62, so that the light beam emitted from the free end of the first optical fiber 1 and passing through the first connecting line 71, after being reflected by the first off-axis parabolic mirror 3, the second off-axis parabolic mirror 4, and multiple reflectors 5, passes through the third connecting line 73 and is gathered by the free end of the second optical fiber 2.

[0037] For the above structure, during installation, reflectors 5 with corresponding numbers and angles can be set according to the position and angle requirements of the first optical fiber 1 and the second optical fiber 2 in the actual optical path, and installed in the corresponding prefabricated body 6, so that during actual use, the positions of the first optical fiber 1 and the second optical fiber 2 inserted into the body 6 are in a state that meets the needs of convenient operation.

[0038] During the use of this embodiment, if the optical path needs to be calibrated, the operator can push the first off-axis parabolic mirror 3 so that the first off-axis parabolic mirror 3 slides slightly forward and backward in the first slide groove 61 of the body 6, or / and simultaneously push the second off-axis parabolic mirror 4 so that the second off-axis parabolic mirror 4 slides slightly forward and backward in the second slide groove 62 of the body 6, so as to adjust the overall optical path to meet the following requirements: Figure 1As shown, starting from the free end of the first optical fiber 1, the first connecting line 71 can be connected to the free end of the second off-axis parabolic mirror 4 after passing through the second connecting line 72, the fifth connecting line 75, the fourth connecting line 74, and the third connecting line 73 in sequence, so as to achieve a complete optical path. Then, the object to be detected is passed into the detection area at the middle position of the body 6, and the first optical fiber 1 can be started to emit detection light to detect the object to be detected.

[0039] In the above process, in the face of spectral baseline deviation caused by multiple plugging and unplugging, when adjustment is needed, it is only necessary to slightly slide the first off-axis parabolic mirror 3 and the second off-axis parabolic mirror 4 back and forth until the optical path meets the preset requirements, thereby avoiding the situation where the existing off-axis reflective optical path cannot be quickly calibrated, and significantly improving work efficiency.

[0040] See also Figure 3-4 , is an absorbance curve diagram of the near-infrared spectrometer of this embodiment. Specifically, a comparative test is performed using a lens transmission light path and an off-axis reflective light path of the present invention, the optical fibers at both ends are plugged in and out repeatedly three times, and the range of the absorbance spectrum baseline drift is recorded. Figure 3 Under the conditions of the lens transmission light path, the dispersion changes during the plugging and unplugging process due to the change in lens positioning, and the absorbance changes show a baseline tilt trend; Figure 4 The off-axis reflective baseline is relatively stable, and the baseline absorbance changes by about 0.015. That is to say, with the intervention of the first off-axis parabolic mirror 3 and the second off-axis parabolic mirror 4 of the present invention, the influence of the dispersion effect can be effectively reduced. At the same time, in order to solve the problem of baseline drift caused by repeated plugging and unplugging of optical fibers, calibration can be achieved by directly sliding and adjusting the first off-axis parabolic mirror 3 and the second off-axis parabolic mirror 4, which significantly improves the detection efficiency.

[0041] Further, the number of the reflectors 5 is two, and the two reflectors 5 are arranged parallel to each other, so that the first connecting line 71 and the third connecting line 73 are parallel, the second connecting line 72 and the fourth connecting line 74 are parallel, and the second connecting line 72 and the fourth connecting line 74 are connected to form a fifth connecting line 75, and the fifth connecting line 75 passes through the center position of the area to be detected of the body 6. For details, please refer to Figure 1With the help of two parallel reflectors 5 arranged in the middle of the main body 6, the positions of the first optical fiber 1 and the second optical fiber 2 are adjusted to the front and rear ends in the horizontal direction after two more reflections of the optical path, so as to facilitate the wiring of the optical fibers. Specifically, the lifting angle of the two reflectors 5 is set to 45 degrees, so that in the conventional wiring condition where the first optical fiber 1 and the second optical fiber 2 are vertically inserted into the main body 6, the fifth connecting line 75 formed between the two reflectors 5 is perpendicular to the detection area of ​​the horizontal plane, which is convenient for the standardization of the detection. At the same time, the two reflectors 5 have sufficient dimensions in the horizontal direction, which can also facilitate the placement of the object to be detected, avoiding the problem of the tight space in the detection area of ​​the main body 1 when there is no reflector 5.

[0042] Furthermore, a concave first screw hole 31 is provided on the surface of the first off-axis parabolic mirror 3 facing the outside of the body 6. When the first off-axis parabolic mirror 3 moves to a preset position in the first slide groove 61, a first baffle plate having a size larger than the aperture of the first slide groove 61 is provided outside the first slide groove 61, and a first fastener is passed through the first baffle plate and fixed in the first screw hole 31, so that the first off-axis parabolic mirror 3 is fixed; similarly, the second off-axis parabolic mirror 4 is also fixed to the body 6 by the same method through the combination of the second screw hole 32 and the second cover plate. The mechanical fixing method of the fastener has high maintenance convenience and is simple and easy to disassemble and assemble.

[0043] In another embodiment, the adjusted first off-axis parabolic mirror 3 and the second off-axis parabolic mirror 4 can also be fixed by gluing. Compared with the method of mechanical fixation by fasteners, the fixing method of this embodiment has lower cost and can be selected according to actual needs.

[0044] Furthermore, the first off-axis parabolic mirror 3 and the second off-axis parabolic mirror 5 are configured to be identical. Figure 1-2 The overall main body 6 structure shown is configured as an up and down rotating mirror structure, that is, the first off-axis parabolic mirror 3 and the second off-axis parabolic mirror 4 are replaceable, the two reflectors 5 are replaceable, and even some modules of the main body 6 are replaceable, which reduces production costs and makes maintenance easier.

[0045] Furthermore, the first off-axis parabolic mirror 3 and the second off-axis parabolic mirror 4 are 90-degree off-axis parabolic mirrors, that is, the first slide groove 61 for installing the first off-axis parabolic mirror 3 and the first slot for installing the first optical fiber 1 in this embodiment are set to 90 degrees, and the second slide groove 62 for installing the second off-axis parabolic mirror 5 and the second slot for installing the second optical fiber 2 are set to 90 degrees. The main body 1 as a whole presents a multi-section vertically bent structure, and the module is easier to process and form.

[0046] It is worth noting that in the main body 6, the first optical fiber 1, the second optical fiber 2, the first off-axis parabolic mirror 3, the second off-axis parabolic mirror 4 and the multiple reflectors 5 are all structures that are easy to disassemble through slide grooves, mounting grooves and slots. The purpose is to facilitate later maintenance and temporary and convenient fine-tuning of the optical path to achieve improved detection efficiency.

[0047] Also included is an embodiment of the application of detecting white wine mash with the help of the optical path system of the present invention. Because it is impossible to model the samples online on the production line before testing mash with different formulas, it is necessary to model the samples offline. After the modeling is completed, the whole machine is put on the production line for use. In the above process, considering the baseline tilt phenomenon, it is generally necessary to perform a secondary calibration of the near-infrared model, which affects the production efficiency. In this embodiment, the preset off-axis reflective optical path system is installed to the key points on the production line, and the optical path of the optical path system is calibrated, and then the key components of the mash are analyzed many times. Specifically, the key components of the mash include but are not limited to acidity (total acid), protein content, total esters, starch, moisture content, etc. Since the off-axis reflective optical path with a more stable baseline is used in this embodiment, the model does not need to be calibrated twice due to the tilt difference between the baseline and the offline modeling. At the same time, each maintenance of the optical path system in this embodiment can maintain better consistency before and after, which is conducive to the stability of the detection output of the optical path system. For the specific method of this embodiment, please refer to Figure 5 .

[0048] The contents disclosed above are only preferred feasible embodiments of the present invention, and are not intended to limit the scope of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention's specification and drawings are included in the scope of the present invention.

[0049] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.

[0050] Although the present application has been described through embodiments, those skilled in the art will appreciate that there are many modifications and changes to the present application without departing from the spirit of the present application. It is intended that the attached embodiments include these modifications and changes without departing from the present application.

Claims

1. An optical path system for reducing the baseline tilt of near infrared spectrum; characterized in that: The optical path system for reducing the near-infrared spectrum baseline tilt comprises: A first optical fiber, a second optical fiber, a first off-axis parabolic mirror, a second off-axis parabolic mirror, a plurality of reflectors and a body; The free end of the first optical fiber is aligned with the focus of the first off-axis parabolic mirror, a first connecting line is formed between the first single-core optical fiber and the focus of the first off-axis parabolic mirror, a second connecting line is formed between the focus of the first off-axis parabolic mirror and one of the corresponding reflectors, and an angle formed between the first connecting line and the second connecting line is the same as the off-axis angle of the first off-axis parabolic mirror; The free end of the second optical fiber is aligned with the focus of the second off-axis parabolic mirror, a third connecting line is formed between the second single-core optical fiber and the focus of the second off-axis parabolic mirror, a fourth connecting line is formed between the focus of the second off-axis parabolic mirror and one of the corresponding reflectors, and an angle formed between the second connecting line and the fourth connecting line is the same as the off-axis angle of the second off-axis parabolic mirror; Wherein, a first slide groove and a second slide groove are provided at both ends of the body, the first off-axis parabolic mirror is installed in the first slide groove, and the first off-axis parabolic mirror can move forward and backward in the first slide groove, the second off-axis parabolic mirror is installed in the second slide groove, and the second off-axis parabolic mirror can move forward and backward in the second slide groove, and by moving the first off-axis parabolic mirror and the second off-axis parabolic mirror, the light beam emitted from the free end of the first optical fiber and passing through the first connecting line passes through the third connecting line after being reflected by the first off-axis parabolic mirror, the second off-axis parabolic mirror, and multiple reflectors and is gathered by the free end of the second optical fiber.

2. The optical path system for reducing the near-infrared spectrum baseline tilt according to claim 1, characterized in that: The number of the reflectors is two, and the two reflectors are arranged parallel to each other, so that the first connecting line is parallel to the third connecting line, the second connecting line is parallel to the fourth connecting line, the second connecting line and the fourth connecting line are connected to have a fifth connecting line, and the fifth connecting line passes through the center position of the area to be detected of the body.

3. The optical path system for reducing the near-infrared spectrum baseline tilt according to claim 1, characterized in that: A first concave screw hole is provided on a surface of the first off-axis parabolic mirror facing the outer side of the body. When the first off-axis parabolic mirror moves to a preset position in the first slide groove, a first baffle plate whose size is larger than the aperture of the first slide groove is covered on the outside of the first slide groove, and the first fastener is passed through the first baffle plate and fixed in the first screw hole, so that the first off-axis parabolic mirror is fixed; a second concave screw hole is provided on a surface of the second off-axis parabolic mirror facing the outer side of the body. When the second off-axis parabolic mirror moves to a preset position in the second slide groove, a second baffle plate whose size is larger than the aperture of the second slide groove is covered on the outside of the second slide groove, and the second fastener is passed through the second baffle plate and fixed in the second screw hole, so that the second off-axis parabolic mirror is fixed.

4. The optical path system for reducing the near-infrared spectrum baseline tilt according to claim 1, characterized in that: The first off-axis parabolic mirror is fixed in the first slide groove by gluing; and the second off-axis parabolic mirror is fixed in the second slide groove by gluing.

5. The optical path system for reducing the near-infrared spectrum baseline tilt according to claim 1, characterized in that: The first off-axis parabolic mirror and the second off-axis parabolic mirror are configured to be identical.

6. The optical path system for reducing the near-infrared spectrum baseline tilt according to claim 1, characterized in that: The first off-axis parabolic mirror and the second off-axis parabolic mirror are 90-degree off-axis parabolic mirrors.

7. The optical path system for reducing the near infrared spectrum baseline tilt according to claim 1, characterized in that: The main body includes a plurality of mounting grooves, and a plurality of the reflectors are detachably mounted in the corresponding mounting grooves.

8. The optical path system for reducing the near infrared spectrum baseline tilt according to claim 1, characterized in that: The main body includes a first slot and a second slot, the first slot is arranged adjacent to the first off-axis parabolic mirror, and the first optical fiber is detachably inserted into the first slot; the second slot is arranged adjacent to the second off-axis parabolic mirror, and the second optical fiber is detachably inserted into the second slot.

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