Refractometer, detection device and method for detecting refractive index

Abstract

A refractometer comprises a light source module (1), a reflection module (2), a convergence module (3), a photosensitive array (4), a control module and a processor; the control module is used to control the light source module (1) to emit a light beam, the reflection module (2) is used to receive the light beam from the light source module (1), and when the light beam from the light source module (1) meets the total reflection condition in the reflection module, the light beam is totally reflected in the reflection module (2) and incident on the convergence module (3); the convergence module (3) is used to converge the light beam from the reflection module (2) onto the focal plane of the convergence module (3); the photosensitive array (4) is located on the focal plane of the convergence module (3), and the control module is further used to control the photosensitive array (4) to detect the received light beam and output a detection image; the processor is used to determine a brightness mutation boundary in the detection image according to the detection image, and to determine the refractive index corresponding to the brightness mutation boundary according to the position of the brightness mutation boundary.

Description

Technical Field

[0001] The invention belongs to the field of liquid refractive index measurement, and in particular relates to a refractometer, a detection device and a method for detecting refractive index. Background Art

[0002] A refractometer is a device that measures the refractive index of a liquid. Since dissolving solid solubles in a liquid increases the liquid's refractive index, refractive index measurement can be used to measure the solid soluble content of the liquid. Since solid solubles in aqueous solutions are typically sugars, refractometers are also called saccharimeters when measuring beverages (such as juice and coffee).

[0003] Figure 1 This is a schematic diagram of the structure of an existing refractometer. The refractometer includes a slit 1', an LED light source 2', a one-dimensional light-sensitive array 3', a triangular prism 4', and a processor (not shown). The principle of the refractometer utilizes the fact that the total reflection angle is determined by the refractive index of the two materials at the interface. When the refractometer is placed in the liquid to be measured, if the refractive index of the liquid to be measured is lower than the refractive index of the triangular prism 4', according to the law of refraction sin(α 折射角 )*n 待测液体 =sin(α 入射角 )*n 三棱镜 It can be seen that the incident angle of the light beam on the side 5' of the triangular prism 4' that contacts the liquid satisfies Total reflection occurs when the light beam enters the surface 5'. That is, when the LED light source 2' is a point light source, in the light beam incident on the surface 5', the part with an incident angle greater than the total reflection angle undergoes total reflection, and when the incident angle is less than the total reflection angle, transmission and reflection coexist, and the brightness of the reflection is smaller than the brightness during total reflection. Therefore, in the one-dimensional image formed by the one-dimensional light-sensitive array 3', pixels at different positions on the image correspond to light beams incident on the surface 5' at different angles from the point light source, and an obvious brightness mutation point can be seen near the pixel corresponding to the light beam incident on the surface 5' at the total reflection angle. The processor can measure the total reflection angle through this brightness mutation point, and calculate the refractive index of the liquid to be tested.

[0004] However, due to process limitations, the light-emitting surface of the LED light source has a certain area. Therefore, the light beams from the LED light source 2′ incident on the surface 5′ at different incident angles may be reflected to the same point on the light-sensitive array 3′, making it impossible to distinguish the angles of these lights, and thus difficult to determine the total reflection angle. Therefore, the existing refractometer is provided with a slit 1′ on the outgoing light path of the LED light source 2′, so that the light source is a very small point light source in the direction parallel to the light-sensitive array 3′, to define the angle of each light beam hitting the light-sensitive array 3′. The slit 1′ essentially decouples the position and direction of the light, so that the refractometer only needs to detect the direction of the light without being disturbed by the position of the light. However, this design will cause the size of the light-sensitive array 3′ to be very large, especially when a relatively large refractive index measurement range is required. The specific reasons are as follows.

[0005] like Figure 2 As shown, the size of the line array 3' is 2*tan(α / 2)*d, where d represents the optical path from the LED light source 2' to the line array 3', and α is the overall angle of the light emitted by the LED light source 2'. When a wide refractive index measurement range is required (for example, when measuring liquids with different refractive indices), α needs to be larger, and therefore the size of the line array 3' must also be increased. This is not conducive to the miniaturization of the refractometer.

[0006] For semiconductor chips such as CCD or CMOS, larger physical dimensions mean higher costs. Considering the limited size of semiconductor wafers, larger device sizes lead to lower shipment rates and yields. Larger chips also mean increased difficulty in packaging and mounting, and increased chip warpage, all of which lead to increased costs. Typically, due to the large semiconductor size requirements, only linear arrays (one-dimensional arrays) can meet cost requirements. However, linear arrays have very high requirements for installation position and accuracy perpendicular to their own direction. When deviations occur in the optical path (caused by thermal expansion and contraction, impact, or mechanical deformation), they cannot automatically correct and are easily affected by ambient light or stray light, resulting in measurement deviations. Summary of the Invention

[0007] The present invention aims to solve the above-mentioned problems by providing a refractometer with low cost, small size, large measurement range, and good robustness, a smart cup equipped with the refractometer, and a method for detecting refractive index. To achieve the above-mentioned objectives, the present invention adopts the following technical solutions: a refractometer comprising a light source module, a reflection module, a convergence module, a photosensitive array, a control module, and a processor; the control module is configured to control the light beam emitted by the light source module; the reflection module is configured to receive the light beam from the light source module. When the light beam from the light source module satisfies a total reflection condition within the reflection module, the light beam undergoes total reflection within the reflection module and enters the convergence module; the convergence module is configured to converge the light beam from the reflection module onto a focal plane of the convergence module; the photosensitive array is located on the focal plane of the convergence module; the control module is further configured to control the photosensitive array to detect the received light beam and output a detection image; and the processor is configured to determine, based on the detection image, a brightness mutation boundary in the detection image and, based on the location of the brightness mutation boundary, determine the refractive index corresponding to the brightness mutation boundary.

[0008] The present invention also provides a detection device comprising the above-mentioned refractometer.

[0009] The present invention also provides a method for detecting refractive index, comprising: emitting a light beam toward a reflection module in a refractometer; converging the light beam that is at least totally reflected by the reflection module to a photosensitive array located on a focal plane of the converging module via a converging module; imaging the received light beam using the photosensitive array to generate a detection image; determining a brightness mutation boundary in the detection image based on the detection image; and determining the refractive index of the medium corresponding to the brightness mutation boundary based on the position of the brightness mutation boundary in the detection image.

[0010] The refractometer of the present invention arranges the photosensitive array on the image-side focal plane of the lens module. The lens module adopts an infinite focus imaging method, so that a non-point light source can be used as the light source. The size of the photosensitive array is shared by the size of the light source, so that the size of the photosensitive array can be very small. It has the advantages of low cost, small size, large measurement range and good robustness. Moreover, the refractometer adopts an area array CMOS detection image sensor, which is lower in cost, higher in accuracy, reduces installation requirements, and can achieve many things that one-dimensional sensors cannot do, such as improving accuracy, enhancing anti-interference ability, and adding other measurement functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0012] Figure 1 It is a structural schematic diagram of an existing refractometer; Figure 2 For the general Figure 1 The schematic diagram of the side where the sensitive light array is equivalent to the liquid surface; Figure 3 A schematic cross-sectional view of a structure of a refractometer; Figure 4 Schematic diagram of the imaging principle of the lens unit using infinity focus; Figure 5 It is a schematic diagram of an equivalent optical system of a refractometer; Figure 6 and Figure 7 They are schematic diagrams of the structures of refractometers using light source modules and lens modules of different sizes in this application; Figure 8 It is the detection image formed by the light beam received by the photosensitive array when the refractometer detects a liquid to be tested; Figure 9 is a schematic structural diagram of an example of a refractometer; Figure 10a ~c is a schematic diagram of the experimental results of the change of the refractive index of a shadowless glue and water with temperature; Figure 11 and Figure 12 Schematic diagrams of two examples of detection images; Figure 13 for Figure 9 An example of a top view of the refractometer shown; Figure 14 A schematic diagram of the positional relationship between the prism, the coating on the prism surface, the waterproof component, and the liquid to be measured; Figure 15-17 A schematic diagram of the detection image; Figure 18 On the left is a pixel value curve of a pixel row on the detection image formed by the light beam received by the photosensitive array; Figure 19 This is a schematic diagram of the structure of a smart cup; Figure 20 It is a structural diagram of an intelligent scale; Figure 21 This is a schematic diagram of an embodiment of a method for detecting the refractive index of a liquid to be measured using a refractometer in the present application. DETAILED DESCRIPTION

[0013] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with certain aspects of the present invention, as detailed in the appended claims.

[0014] The terms used in this invention are for the purpose of describing specific embodiments only and are not intended to limit the invention. The singular forms "a," "the," and "the" used in this invention and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0015] It should be understood that although the terms first, second, third, etc. may be used in the present invention to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other.

[0016] The following describes an example structure of a refractometer in the present application. In this example, compared to the prior art method of providing a small hole at the light source output end to achieve decoupling of the angle and position of the incident light beam of the sensitive light array in one dimension (i.e., the direction parallel to the sensitive light array), this embodiment uses a convergence module located on the light beam incident side of the photosensitive module to achieve decoupling of the angle and position of the incident light beam of the photosensitive module. Moreover, the convergence module can achieve decoupling in two dimensions. Therefore, the photosensitive module can use a photosensitive surface array to detect the light beam, thereby achieving the refractive index detection optical path for self-calibration and the refractive index detection optical path for the liquid to be measured. The light source and photosensitive surface array can be shared, thereby avoiding calculation deviations caused by offsets between the two detection optical paths (for example, offsets caused by poor consistency of semiconductor chips, poor consistency of mounting structures, installation deviations, mechanical shock, or temperature drift, etc.).

[0017] In addition, by adding a convergence module in front of the photosensitive array and utilizing infinity focus to decouple the position and direction of the light, the light source module does not need to be very small in order to achieve the goal of converging the light emitted from the reflection module at one exit angle to the same position on the sensor. In the prior art, since the divergence angle of the light source module is required to be large, but the divergence angle of the LED light source itself is not very large, the solution using the prior art requires finding a special LED light source with a large angle and a small light-emitting surface. Compared to the prior art, the light source module in this application does not need to bear the function of distinguishing angles and positions, and there are fewer restrictions on the selection of the light-emitting unit in the light source module.

[0018] Moreover, compared to the prior art, which requires a linear array for detection due to the arrangement of the pinholes, the present embodiment uses a planar array to detect the light beam, which can obtain more information than a linear array, which is beneficial for improving the accuracy of the refractive index of the liquid to be tested, and can even obtain more information about the liquid to be tested. Moreover, the refractometer uses a planar array CMOS detection image sensor, which is lower in cost, higher in accuracy, reduces installation requirements, and can achieve many things that one-dimensional sensors cannot do, such as improving accuracy, enhancing anti-interference capabilities, and adding other measurement functions. Moreover, compared to the prior art refractometer, which requires the reflection properties of the total reflection surface interface to remain consistent within the liquid surface range, because the present application can directly measure the direction of the light, even if there are bubbles at the detection surface of the prism or the liquid to be tested does not completely cover the total reflection interface, the brightness mutation boundary is still clearly distinguishable.

[0019] Since the refractive index of the liquid will drift with the change of temperature, there will be deviations when determining the solid soluble content of the liquid based on the refractive index of the liquid. In order to ensure the accuracy of the refractometer measurement, an existing solution is to calibrate the brightness mutation point corresponding to a liquid of a fixed concentration (such as a liquid of 0 Brix) in the image formed by the refractometer's light-sensitive array to ensure the measurement accuracy of the refractometer. Specifically, the position of the 0 Brix brightness mutation point is preset in the refractometer. The refractometer forms a brightness mutation point on the image of the light-sensitive array as a self-calibration position by measuring clean water in real time. Then, when the refractometer measures the refractive index and solid soluble content of the liquid to be measured, the real-time measurement result is corrected according to the 0 Brix brightness mutation point and the self-calibration position; but this requires self-calibration with clean water before measurement. If simultaneous measurement and calibration are to be achieved using existing calculation methods, the need for a self-calibration position requires two emitting light sources and corresponding two light-sensitive arrays: one for detecting the self-calibration liquid, and the other for detecting the test liquid. However, during use, the refractometer uses two different structures for detecting the self-calibration liquid and the test liquid. This can easily lead to inaccurate self-calibration results due to the offset of the two detection light paths in the refractometer, resulting in calculation errors.

[0020] The refractometer in this embodiment can also use a second medium fixed within the reflective module to replace the clear water used in the prior art as a self-calibration object. By fully reflecting the light beam before it enters the second medium, a brightness abrupt boundary is formed on the image formed by the photosensitive array, thereby measuring the refractive index of the second medium. The measurement results of this second medium are then used to correct the measurement results of the liquid being measured. Compared to the prior art, the combination of the focusing module and the photosensitive array decouples the position and direction of the light beam. Furthermore, the photosensitive array is two-dimensional, allowing the second medium and the liquid being measured to be detected using the same receiver. Even the same light source can be used to form the brightness abrupt boundary corresponding to the second medium and the liquid being measured on the photosensitive array. This avoids measurement errors caused by differences in different photosensitive arrays and optical paths in the prior art, thereby improving the accuracy of the refractometer's measurement results. Furthermore, by introducing a second medium to calibrate the refractive index of the liquid being measured, the refractometer in this embodiment eliminates the need for clear water calibration, enabling more accurate measurement of high-temperature liquids and offering a wider range of applications.

[0021] Below Figure 3 The embodiment shown is described in detail. Figure 3 The cross-sectional diagram of a refractometer structure is shown in FIG. Figure 3 As shown, the refractometer includes a light source module 1, a reflection module 2, a convergence module 3, a photosensitive array 4, a control module (not shown) and a processor (not shown). The control module is used to control the light source module 1 to emit a light beam, and to control the photosensitive array 4 to perform light detection. Optionally, the control module includes a light source controller and a photosensitive controller, which are used to control the light source module 1 and the photosensitive array 4 respectively. The reflection module 2 is used to receive the light beam from the light source module 1. After the light beam from the light source module 1 is incident on the reflection module 2, when the total reflection condition is met, the light beam with an incident angle greater than or equal to the total reflection angle is totally reflected, and the light beam with an incident angle less than the total reflection angle is partially transmitted and partially reflected. The reflected and totally reflected light beam is emitted from the reflection module 2 and then incident on the convergence module 3. The convergence module 3 is used to converge the light beam from the reflection module 2 to the photosensitive array 4 located on the focal plane of the convergence module 3. The control module is also used to control the photosensitive array 4 to detect the received light beam and output a detection image.

[0022] The converging module 3 can be a single lens, in which case the focal plane of the converging module 3 refers to the focal plane of the lens; or it can be a lens assembly consisting of at least two lenses, in which case the focal plane of the converging module 3 refers to the equivalent focal plane of the lens assembly. In the case of a lens assembly, the optical design of the lenses can also be used to reduce aberrations and distortions in the converging module's imaging.

[0023] The following combination Figure 4 Take the convergence module as an example to explain the function of the convergence module. Figure 4 As shown, ideally, parallel light can be converged by a lens to a convergence point on the focal plane. This convergence point is the intersection of the optical center of the lens extending in the direction of the parallel light and the focal plane. Therefore, this convergence point is only related to the direction of the light and has nothing to do with the exit position of the light. Utilizing this principle, this embodiment decouples the position and direction of the light by providing a convergence module in front of the photosensitive array 4. This allows light in any plane passing through the optical center of the convergence module to be totally reflected at different positions of the reflection module at the same exit angle within the plane to converge at the same position of the photosensitive array 4, ultimately forming a brightness mutation boundary corresponding to the total reflection angle on the photosensitive array 4. Due to the provision of the convergence module, different positions of the brightness mutation boundary in the detected image correspond to light beams that are totally reflected at different total reflection angles. Therefore, the processor can determine the total reflection angle corresponding to the brightness mutation boundary by obtaining the position of the brightness mutation boundary, and then calculate the corresponding refractive index based on the total reflection angle.

[0024] In one example, the light source module 1 includes an LED light bar, or a light source composed of a plurality of LED lamp beads combined by patching or packaging. The wavelength of the LED needs to be compatible with the wavelength response of the CMOS photosensitive array, and the wavelength can be between 300nm and 1000nm, for example, the wavelength can be between 400nm and 500nm, or between 500nm and 600nm, or between 600nm and 700nm, or between 700nm and 800nm, or between 800nnm and 900nm. Optionally, the wavelength of the LED is in the green light band, for example, the center wavelength is between 500nm and 600nm. Since a common photosensitive area array on the market is a CMOS sensor with an RGGB Bayer pattern, this type of photosensitive area array will have higher resolution and greater sensitivity to the G channel, and the use of the green light band can better cooperate with the photosensitive area array.

[0025] In one example, if Figure 3 As shown, a filter 7 that matches the output light of the light source module 1 is provided on the optical path between the detection surface of the reflector module 2 and the photosensitive array 4. The filter 7 is used to transmit the output light of the light source module 1 and reflect light beams of other wavelengths to reduce the interference of background light on the detection results. Optionally, the output light of the light source module 1 is of a single wavelength to make it easier to match a narrowband filter for background light elimination.

[0026] In one example, the reflection module 2 includes a first medium 21. The refractometer also includes a detection area disposed on a surface of the first medium, configured to support the liquid 5 to be tested when the refractometer detects the liquid 5. When the detection area is covered with the liquid to be tested, and the refractive index of the liquid to be tested is lower than that of the first medium, at least a portion of the light beam is totally reflected by the liquid to be tested. The processor can calculate the refractive index of the liquid to be tested based on the location of the brightness change boundary corresponding to the totally reflected light beam in the detection image.

[0027] The first medium can be a prism, and the prism 21 includes a light incident surface 212, a detection surface 211, and a light exit surface 213, and the detection area is set on the surface of the detection surface 211. The light beam from the light source module 1 is incident on the detection surface 211 of the prism 21 from the light incident surface 212. When the refractive index of the object 5 on the detection area is lower than the refractive index of the prism, and the incident angle of the light beam on the detection surface 211 meets certain conditions, the light beam is totally reflected on the detection surface 211 and is emitted from the light exit surface 213. Optionally, the prism 21 is a triangular prism. Optionally, the prism 21 is an isosceles prism, for example, an isosceles right-angle prism, so that the prism structure is more compact, making the overall structure more miniaturized.

[0028] Optionally, an anti-reflection film is provided on the light incident surface 212 and the light exit surface 213 of the prism to improve the transmittance of the light beam. The prism 21 can be made of glass material, or can also be made of other transparent materials such as plastic, resin, etc. Optionally, the size of the detection area matches the divergence angle of the output light of the light source module 1, so that the light spot formed by the output light on the detection area just covers the detection area or is slightly smaller than the detection area, so as to facilitate the miniaturization of the refractometer. In other examples, the first medium can also be other optical elements with a high refractive index, or be composed of other media with a high refractive index.

[0029] The field of view of the lens is determined by the focal length f and the aperture size d of the lens. However, the refractometer's ability to achieve a large refractive index detection range for the liquid under test depends not only on the field of view of the lens, but also on ensuring that the light within the field of view can be reflected by the reflection module and incident on the convergence module. Therefore, the size of the light-emitting surface of the light module needs to be increased accordingly. The angle range of the light beam that the convergence module can receive is ultimately determined by the size of the light-emitting surface of the light source module and the size of the convergence module. Figure 5 In the equivalent optical system, the focusing module 3, the photosensitive array 4 and the processor are mirrored to the side of the reflection module facing away from the light source module 1, and the focusing module 3 is illustrated as an equivalent lens.

[0030] like Figure 5As shown, the angle range α that the photosensitive array 4 can detect is defined by two lines on the edge: the light r1 from the top of the light emitting surface of the light source module 1 to the bottom of the light aperture of the lens 3, and the light r2 from the bottom of the light emitting surface of the light source module 1 to the top of the light aperture of the lens. This angle range α is determined by three variables: the size of the light emitting surface of the light source module 1, the light aperture of the lens 3, and the distance between the light emitting surface of the light source module 1 and the lens 3. Therefore, when the detection angle range α of the photosensitive array 4 is the same, compared Figure 1 In the refractometer with a slit design shown in the figure, the size of the photosensitive array in this application can be shared by the size of the light-emitting surface of the light source module 1 and the aperture of the lens. That is, when the detection angle range α of the photosensitive module in one dimension is the same, Figure 1 The aperture of the photosensitive module in the refractometer shown in this dimension is the aperture of the light-emitting surface of the light source module 1 in this application + the clear aperture of the lens. Therefore, compared to the existing technology, this application can achieve smaller light source modules and photosensitive modules within the same detection angle range, thereby miniaturizing the product and reducing costs. Furthermore, this application can choose to share the size of the photosensitive array with the size of the light source, making the size of the photosensitive array very small, with the advantages of low cost and small size.

[0031] In one example, the aperture of the light emitting surface of the light source module 1 is greater than or equal to the aperture of the light converging module 3. Figure 6 As shown, the aperture of the light-emitting surface of the light source module 1 and the clear aperture of the converging module 3 are the same, or differ by less than 1 / 5 of the aperture of the light-emitting surface. Thus, while the detection angle range α of the photosensitive array 4 is the same, the aperture of the photosensitive array in the refractometer of the present application is half that of the photosensitive array in the prior art, which can reduce the cost and difficulty of mass production of the refractometer.

[0032] For example, Figure 7 As shown, the aperture of the light-emitting surface of the light source module 1 is greater than twice the clear aperture of the focusing module 3. Thus, under the condition that the detection angle range α of the photosensitive array is the same, the aperture of the photosensitive array in the refractometer of the present application can be made very small. Since increasing the size of the light source module requires much less cost and mass production difficulty than increasing the size of the photosensitive array, by allowing the light source module to bear more size, the cost and mass production difficulty can be further reduced.

[0033] Optionally, the detection angle range α of the photosensitive array covers the total reflection angle range of the reflection module, where the total reflection angle range of the reflection module refers to all angles at which total reflection can occur within the reflection module, thereby ensuring a large refractive index detection range for the refractometer. Optionally, the reflection module uses a high-refractive-index medium to reduce the total reflection angle range of the convergence module. However, since high-refractive-index glass has more severe dispersion, this is because when light of different wavelengths passes through the glass, the high-refractive-index reflection module causes the refractive index of the light beams of different wavelengths to vary significantly. This in turn causes the total reflection boundary in the detection image acquired by the photosensitive array to become blurred, reducing the detection accuracy of the total reflection angle. In one example, the refractometer can use a light source module with a narrow wavelength bandwidth, or set a narrowband filter on the output light path of the light source module to reduce the wavelength bandwidth of the output light of the light source module to reduce dispersion. For example, the output light of the light source module or the output light after filtering by the narrowband filter is a beam with a half-height width of less than 5nm.

[0034] like Figure 8 As shown, Figure 8 It is the detection image formed by the light beam received by the photosensitive array when the refractometer detects a liquid to be tested. The refractometer is placed in the liquid to be tested so that the detection area is covered by the liquid to be tested and the photosensitive array forms a detection image. Figure 8 As shown, the detection image includes a reflection area 81 and a non-reflection area 82 surrounding the reflection area 81. The reflection area 81 includes a total reflection area 811 and a non-total reflection area 812. The total reflection area 81 refers to the area in the reflection area 81 of the detection image 8 where the light beam that is totally reflected by the total reflection interface 21 of the reflection module 2 is incident, and the non-total reflection area 812 refers to the area in the detection image 8 where the light beam that is reflected when incident on the total reflection interface 21 of the reflection module 2 at an angle less than the total reflection angle is incident. Since the reflected portion of the light beam that is not totally reflected has a sudden drop in brightness compared to the light beam that is totally reflected, an obvious brightness mutation boundary 813 is formed at the junction of the total reflection area 812 and the non-total reflection area 811. The brightness mutation boundary 813 corresponds to the light beam that is incident at the total reflection angle at the total reflection interface 21.

[0035] Due to the setting of the convergence module, different pixel positions in the detection image correspond to light beams emitted from the total reflection interface at different angles. Therefore, the processor can determine the position of the brightness mutation boundary by obtaining the position of at least one pixel point in the brightness mutation boundary, and then calculate the refractive index of the liquid to be tested based on the total reflection angle corresponding to the position of the brightness mutation boundary.

[0036] In this application, the position and direction of the light are decoupled by adding a lens module in front of the photosensitive array, so the light source module does not need to be very small. As long as there is light at the corresponding angle, it can be focused on the corresponding sensor position. Compared with the existing technology, the light source module in this application does not need to bear the function of distinguishing angles and positions. In the existing technology, since the divergence angle of the light source module is required to be large, but the divergence angle of the LED light source itself is not very large, the solution of the existing technology needs to find a special LED light source with a large angle and a small light-emitting surface. However, since the requirements for the light source module in this application are much more relaxed, a large-angle light-emitting range can be achieved by multiple LEDs + a uniform light plate. In one example, such as Figure 3 As shown, the light source module 1 also includes a light homogenizer 6 located on one side of the light-emitting surface. Since the photosensitive array senses light beams from different directions, the light homogenizer can improve the uniformity of the light beams in each direction, thereby improving the uniformity of the image formed by the photosensitive array, and can also avoid the problem of reduced measurement accuracy due to inconsistent light intensity at different angles.

[0037] In some examples, the reflection module includes two adjacent media, which may be media other than the first medium or may include the first medium; and by causing the outgoing light beam of the light source module to form a total reflection between the two adjacent media, a brightness mutation boundary is formed on the detection image in addition to the brightness mutation boundary corresponding to the liquid to be tested, which is used to correct the refractive index of the liquid to be tested, so as to reduce the calculation deviation of the refractive index of the liquid to be tested caused by the drift of the refractive index of the liquid with the change of temperature, thereby improving the calculation accuracy of the refractive index of the liquid to be tested. Figure 9 The structure of an example of the refractometer of the present application is described as an example.

[0038] Figure 9 The schematic diagram of the structure of an example of a refractometer is shown in FIG. Figure 9 As shown, in this embodiment, the light source module 1 is used to emit a first light beam and a second light beam. The reflection module includes at least two media for receiving the light beam from the light source module. Specifically, the reflection module includes a first medium 21 and a second medium 22 arranged adjacent to each other. The refractive index of the first medium 21 is greater than the refractive index of the second medium 22, and a first total reflection area exists between the first medium 21 and the second medium 22. The reflection module also includes a detection area 23 arranged above the first medium 21. Optionally, the second medium 22 and the detection area 23 are respectively arranged in different areas on the same surface of the first medium 21.

[0039] The first medium is used to receive the first light beam and the second light beam. At least a portion of the first light beam is incident from the first medium 21 to the second medium 22. Since the refractive index of the first medium 21 is greater than the refractive index of the second medium 22, and the emission angle of the first light beam is such that the incident angle when incident on the second medium 22 covers the total reflection angle, at least a portion of the second light beam incident on the second medium 22 is totally reflected within the first total reflection area. When one side of the detection area 23 is covered with the liquid to be measured 5, at least a portion of the second light beam is incident from the first medium 21 to the liquid to be measured. When the refractive index of the liquid to be measured is greater than the refractive index of the first medium 21, and the divergence angle of the second light beam satisfies the condition that the incident angle when incident on the second medium 22 covers the total reflection angle, the portion of the second light beam that satisfies the total reflection condition in the second light beam incident on the detection area 23 is totally reflected on the detection area 23.

[0040] The light source module 1 may include one or at least one light emitting unit (e.g., LED). In the case where the light source module 1 includes multiple light emitting units, the first light beam and the second light beam may be from different emission units in the light source module 1, or may be light beams with different emission angles from all emission units in the light source module 1. Figure 9 In the figure, the first light beam and the second light beam are respectively derived from light beams with different emission angles from all the emission units in the light source module 1. For example, the light L111 in the light beam emitted by the emission unit 11 and the light L121 in the light beam emitted by the emission unit 12 belong to the first light beam, and are totally reflected when incident on the second medium 21; the light L112 in the light beam emitted by the emission unit 11 and the light L122 in the light beam emitted by the emission unit 12 belong to the second light beam, and are totally reflected when incident on the detection area 23.

[0041] Optionally, the emission angle of the first light beam is such that all, or at least 50% of, the incident angles upon entering the second medium 22 are greater than or equal to the total internal reflection angle, resulting in total or nearly total internal reflection within the first total internal reflection zone, thereby enhancing brightness contrast at the brightness abrupt change boundary. Optionally, the area of ​​the second medium 22 matches the divergence angle of the first light beam, such that the light spot formed by the first light beam on the second medium 22 just covers the second medium 22 or is slightly smaller than the second medium 22, thereby facilitating miniaturization of the refractometer.

[0042] Figure 9In the example shown, the first medium 21 is a prism. The second medium 22 is a coating laid on a surface of the first medium 21. The surface is divided into a first area and a second area side by side. The second medium 22 is fixed on the side of the first area facing away from the light source module, and the second area is not covered with the second medium 22, which is the detection area 23. When the refractometer measures the liquid to be measured, the liquid to be measured covers the second area. Optionally, a liquid tank is provided on the surface of the first medium 21, and the second medium is provided on a partial area of ​​the liquid tank by a spraying process, a printing process or other process, and the remaining area of ​​the liquid tank is set as the detection area 23. In some examples, the second medium also needs to be waterproofed. For example, after the first area of ​​the liquid tank is coated, a light-transmitting waterproof material (such as a glass sheet) 24 is added to cover only the first area, or to cover the entire liquid tank.

[0043] In some examples, the second medium can be made of a material whose refractive index varies with temperature and has a high correlation with that of water, thereby improving the accuracy of the refractive index calibration of the measured liquid. Optionally, the refractive index of the second medium varies with temperature within a range of -0.0003 / deg C to 0.0003 / deg C.

[0044] The second medium can be a liquid, for example, clean water, which is sealed and fixed in a liquid tank on the surface of the prism. The second medium can also be a solid, such as a light-curing coating, a high-temperature curing coating or a natural curing coating, etc. The high-temperature curing coating can be polytetrafluoroethylene (PTFE) that has been cured at high temperature. The natural curing coating can be a fluorocarbon resin FEVE coating that has been cured naturally. The light-curing coating can be a light-cured shadowless adhesive. The refractive index of the shadowless adhesive has a high correlation with the temperature change characteristics and the refractive index of clean water has a high correlation with the temperature change characteristics. Using the measurement results of the shadowless adhesive to calibrate can improve the accuracy of the refractive index measurement of the liquid to be measured. For example Figure 10a As shown in ~c, Figure 10a Figure ~c is a schematic diagram of the experimental results of the refractive index of a shadowless glue and water changing with temperature. Figure 10a This is a schematic diagram of the experimental results showing that the refractive index of shadowless adhesive drifts with increasing temperature. Figure 10b This is a schematic diagram of the experimental results showing that the refractive index of water drifts with increasing temperature. Figure 10c Schematic diagram showing the distribution of refractive index difference at various temperatures. Figure 10aThe ordinate in [c] represents the position of the brightness change boundary corresponding to the refractive index in the detection image, and the abscissa represents the number of times. Different positions correspond to different refractive indices, and different numbers correspond to different temperatures. The figure shows that the refractive index of both the adhesive and water has a high correlation with temperature. Furthermore, the adhesive has advantages such as high transmittance and low expansion rate. Optionally, the refractive index of the cured adhesive is greater than 1.33 and not greater than 1.6.

[0045] There can be various positional relationships between the first area and the second area of ​​the first medium. Figure 9 In the illustrated embodiment, the divergence angle of the light beam emitted by the light source module 1 is maximum or near maximum in a cross section parallel to the paper, and minimum in a cross section perpendicular to the paper. To coordinate the light emitted by the light source module, the first and second regions are arranged along the width direction of the two regions (also perpendicular to the paper), and the second region can cover the divergence angle of the light emitted by the light source module 1 along the length direction of the two regions (also parallel to the paper). This allows the second region to measure a wider range of total reflection angles, thereby increasing the refractive index measurement range. It also allows the overlap between the first imaging area of ​​the second light beam and the second imaging area of ​​the first light beam in the photosensitive array 4 to be narrower, reducing the degree of mutual interference between the first and second imaging areas. Of course, the first and second regions can also have other positional relationships. In this embodiment, since the first region only needs to cover the total reflection angle corresponding to the second medium, the second region preferably covers as wide an incidence angle range as possible for the first light beam to achieve a wider refractive index measurement range.

[0046] The total reflection of the first light beam in the first total reflection area will cause a first brightness mutation boundary to be fixedly formed in the imaging of the photosensitive array. When the liquid to be tested meets the total reflection condition, the total reflection of the second light beam between the liquid to be tested and the medium on one side will cause a second brightness mutation boundary to be formed in the imaging of the photosensitive array. Specifically, the imaging of the photosensitive array includes a first imaging area corresponding to the incidence of the first light beam and a second imaging area corresponding to the incidence of the second light beam. The first imaging area includes areas located on both sides of the first brightness mutation boundary, one side has higher brightness, corresponding to the total reflection of the partial light beam (for the convenience of description, hereinafter referred to as the total reflection area), and the other side has lower brightness, corresponding to the non-total reflection of the partial light beam (for the convenience of description, hereinafter referred to as the non-total reflection area). Similarly, the second imaging area includes the total reflection area and the non-total reflection area located on both sides of the second brightness mutation boundary.

[0047] Among them, Figure 11 As shown, the first imaging area P1 and the second imaging area P2 can be two areas separated from each other without intersection in the imaging, which can reduce the mutual interference between the first brightness mutation boundary L1 and the second brightness mutation boundary L2, making it easier for the processor to detect the two boundaries. Figure 12 As shown, the image may also contain two overlapping or even overlapping regions. In this case, as long as the refractive indices of the liquid to be measured and the second medium are different, the positions of the first brightness mutation boundary L1 and the second brightness mutation boundary L2 will differ. The processor can identify the first and second brightness mutation boundaries based on the brightness changes. Optionally, the first brightness mutation boundary is located near an edge in the detected image. Optionally, the detected image includes a first and second opposing edges, wherein the closer the brightness mutation boundary in the detected image is to the first edge, the higher the refractive index. The first brightness mutation boundary is located between the first edge in the detected image and the brightness mutation boundary corresponding to the maximum refractive index within the refractive index measurement range of the refractometer. This ensures the maximum refractive index measurement range of the refractometer while maintaining a fixed FOV of the photosensitive array. Optionally, the distance between the first brightness mutation boundary and the first edge is greater than 1 / 10 of the width of the detected image, and the distance from the brightness mutation boundary corresponding to the maximum refractive index measurement range of the refractometer is greater than 1 / 8 of the width. This ensures the measurement accuracy of both the first and second brightness mutation boundaries.

[0048] There are many ways to realize that the first imaging area and the second imaging area are two separate areas without intersection. In some examples, a structure can be set on the optical path before the convergence module 3 to separate the optical paths of the second light beam and the first light beam, thereby making the first imaging area and the second imaging area two separate areas. Figure 9 In the example shown, a light inlet 2111 is provided on the light incident surface of the prism 21 to restrict the light beam from the light source module 1 to only be incident on the interior of the prism 21 through the light inlet 2111. A first light outlet 2121 and a second light outlet 2122 are provided on the light exit surface of the prism 21 for light beam exit. The area outside the first light outlet 2121 and the second light outlet 2122 is provided with a material that reflects or absorbs the light beam. The first light outlet 2121 is located on the optical path of the first light beam that has been totally reflected and reflected by the second medium 22, and the second light outlet is located on the optical path of the second light beam that has been totally reflected and reflected by the liquid to be tested in the detection area 23.

[0049] In one example, if Figure 13 As shown, Figure 13 for Figure 9An example of a top view of a refractometer is shown. In this example, the lower edge of the first light outlet 2121 is located above the extension line of the upper edge of the light entrance 2111, and the upper edge of the second light outlet 2122 is located below the extension line of the lower edge of the light entrance 2111. This reduces the proportion of the first light beam emitted from the first light outlet 2121 and significantly reduces the proportion of the second light beam emitted from the second light outlet 2122. Consequently, the light beams emitted from the first light outlet 2121 and the light beams emitted from the second light outlet 2122 are converged by the convergence module and respectively incident on two different areas of the photosensitive array, so that the first imaging area and the second imaging area formed on the image formed by the photosensitive array are separated and do not overlap.

[0050] Of course, the lower edge of the first light outlet and the upper edge of the second light outlet may not be subject to this restriction. Even if the second light beam and the first light beam emitted from the light outlet of the reflection module cannot be completely separated, the degree of mutual interference between the first imaging area and the second imaging area can still be reduced compared to the solution without a light outlet.

[0051] The first light outlet and the second light outlet can be realized by silk-screening on the light outlet surface of the converging module, or by installing a structural member on the light outlet surface or on one side of the light outlet surface of the converging module, which is not limited here.

[0052] In some examples, the brightness of the central area of ​​the photosensitive array differs from that of the surrounding areas due to the light distribution characteristics of the light emitted by the light source. Optionally, different exposure parameters (such as different exposure intensities, different exposure times, or different exposure times) are used for different photosensitive cells or photosensitive cells in different areas of the photosensitive array to increase the brightness of darker areas and thereby improve the detection signal-to-noise ratio.

[0053] In some examples, the second medium and the detection zone may not be arranged side by side on the same surface of the first medium, but may be arranged in a stacked relationship. For example, the second medium may be a coating applied to one surface of the first medium, and the detection zone may be located above the second medium, facing away from the first medium.

[0054] The first light beam and the second light beam are incident on the first medium, the second medium and the detection area in sequence. The first medium and the second medium are mainly used to cause the first light beam to produce total reflection, so as to form a first brightness mutation boundary on the detection image; the second medium and the liquid to be tested on the detection area are mainly used to cause the second light beam to produce total reflection, so as to form a second brightness mutation boundary on the detection image. The total reflection angle of the light beam between the first medium and the second medium (hereinafter referred to as the first total reflection angle for the convenience of description) needs to be greater than the total reflection angle between the second medium and the liquid to be tested (hereinafter referred to as the second total reflection angle for the convenience of description). Therefore, the second medium is preferably made of a material with a refractive index greater than the highest point of the measuring range of the liquid to be tested.

[0055] Optionally, by shaping the output light of the light source module 1 or adjusting the luminous brightness of different light-emitting elements of the light source module 1, the proportion of the output light of the light source module 1 whose incident angle when incident on the second medium 22 is less than the first total reflection angle is greater than 50%, so as to reduce the dimming of the brightness of the second brightness mutation boundary corresponding to the liquid to be tested caused by the large amount of attenuation of the output light of the light source module 1 after passing through the second medium.

[0056] Since refractometers are generally required to be waterproof, the second medium can also be made of a material with a waterproof function, and at the same time have a waterproof function to seal the first medium in the refractometer. Alternatively, optionally, a light-transmitting waterproof member is further provided on the side of the second medium facing away from the first medium, which is used to seal the first medium and the second medium in the refractometer, and the detection area is provided on the surface of the waterproof member facing away from the second medium. Moreover, the waterproof member can be made of a material with a higher refractive index to increase the difference in refractive index with the liquid to be measured, thereby reducing the ambient light entering the refractometer and reducing the impact of ambient light on the measurement results. Optionally, the refractive index of the waterproof member is greater than the maximum refractive index in the refractive index measurement range of the refractometer.

[0057] In the example of a waterproof member, if it is too thick, it will affect heat conduction, resulting in the temperature of the liquid to be measured and the second medium not being basically consistent, which will affect the self-calibration effect. On the other hand, if the waterproof member is too thin, it will affect the hardness of the waterproof member. Optionally, the thickness of the waterproof member should be between 0.05 mm and 3 mm to ensure both heat conduction and hardness.

[0058] Compared with the example in which the positional relationship between the second medium and the detection area is set to be the same layer, the positional relationship between the second medium and the detection area is set to be the upper and lower layers, which can simplify the process difficulty, make waterproofing easier, and reduce costs. The waterproof part can be made of glass sheets or other light-transmitting and waterproof materials. Among them, the refractive index of the waterproof part can be greater than the refractive index of the second medium, or it can be less than the refractive index of the second medium. The above description is given by taking the first medium as a prism and the second medium as the coating on the surface of the prism as an example. Of course, the first medium and the second medium in this application can also refer to other elements, which will be further described with examples below. The following is respectively combined with Figures 14 to 17 Explain the three examples. Figure 14 As shown, Figure 14 The figure is a schematic diagram showing the positional relationship among the prism, the coating on the surface of the prism, the waterproof component and the liquid to be measured.

[0059] Example 1: The first medium is a prism, and the second medium is a coating. The refractive index of the second medium is greater than that of the waterproof component. Since total reflection occurs when a light beam enters a light-sparse medium from a dense medium, when the light beam passes through the first medium, the second medium, the waterproof component, and the liquid to be tested on the detection area in sequence, and the refractive index of the liquid to be tested is less than that of the waterproof component, when the light beam covers the total reflection angle between all two adjacent layers, total reflection will occur between any two adjacent layers, thereby forming a corresponding brightness mutation boundary in the detection image. Figure 15 As shown, Figure 15 This is a schematic diagram of a detection image. In the detection image, M1 is the brightness abrupt change caused by total internal reflection of the light beam between the first medium and the second medium, which can be used to calculate the refractive index of the second medium. M2 is the brightness abrupt change caused by total internal reflection of the light beam between the second medium and the waterproofing element, which can be used to calculate the refractive index of the waterproofing element. M3 is the brightness abrupt change caused by total internal reflection of the light beam between the waterproofing element and the liquid being tested, which can be used to calculate the refractive index of the liquid being tested. These three brightness abrupt change boundaries are arranged in order from left to right in the image.

[0060] Optionally, by setting the positional relationship between the photosensitive array 4 and the converging module 3, the position of the light beam totally reflected by the first total reflection area after being converged by the converging module 3 is located outside the photosensitive array 4, so that only M2 and M3 can be displayed in the obtained detection image, such as Figure 16 This can further reduce the interference of the first brightness mutation boundary on the detection of other brightness mutation boundaries; moreover, the distance between M2 and the right edge of the image increases, which can increase the measurement range of the refractive index of the liquid to be measured.

[0061] Example 2: The first medium is a prism and the second medium is a coating. The refractive index of the waterproof component is greater than or equal to the refractive index of the second medium. When the refractive index of the liquid to be tested is less than that of the waterproof component, when the light beam covers the total reflection angle between all two adjacent layers, total reflection will occur between the first medium and the second medium, and between the waterproof component and the liquid to be tested, thereby forming a corresponding brightness mutation boundary in the detection image. Figure 17 As shown, Figure 17 This is another schematic diagram of the detection image. In the detection image, M4 is the brightness abrupt change caused by total internal reflection of the light beam between the first medium and the second medium, which can be used to calculate the refractive index of the second medium. M5 is the brightness abrupt change caused by total internal reflection of the light beam between the waterproof component and the liquid under test, which can be used to calculate the refractive index of the liquid under test.

[0062] Compared with Example 1, in Example 2, since one brightness mutation boundary line is reduced in the image, interference with the detection of the other two brightness mutation boundaries can be reduced, and the measurement range of the refractometer can be increased.

[0063] Example three: The first medium is a coating on the surface of the prism, the second medium is a waterproof component, and the refractive index of the coating is greater than the refractive index of the waterproof component. Therefore, the first total reflection area refers to the total reflection of the first light beam between the coating and the waterproof component, corresponding to the first brightness mutation boundary. The second brightness mutation boundary is generated by the total reflection of the second light beam between the waterproof component and the liquid to be tested on the detection area. The processor corrects the second brightness mutation boundary corresponding to the refractive index of the liquid to be tested through the first brightness mutation boundary formed by the total reflection light beam occurring in the first total reflection area. In this example, the coating preferably uses a material whose refractive index drifts in the opposite direction with temperature changes to the direction in which the refractive index of clean water drifts in the opposite direction with temperature changes.

[0064] In the example where the positional relationship between the second medium and the detection area is set as upper and lower layers, since the light beam has already undergone one total reflection between the first medium and the second medium, the light beam that is totally reflected between the second medium and the liquid to be tested will attenuate more, which may cause the second brightness mutation boundary to be much darker than the first brightness mutation boundary, resulting in a lower signal-to-noise ratio.

[0065] In one example, the photosensitive array is configured to continuously output a detection image sequence comprising multiple detection image frames, wherein different exposure parameters are applied to two adjacent detection image frames. The exposure parameters may include exposure intensity, exposure duration, or number of exposures. The processor is further configured to synthesize a single image frame based on the two adjacent detection image frames for detection, thereby increasing the brightness of the second brightness mutation boundary and improving the signal-to-noise ratio.

[0066] In one example, the photosensitive array is used to continuously output a detection image sequence comprising multiple detection image frames. During the two time periods in which the photosensitive array forms two adjacent detection image frames, the light source module emits different luminous intensities. Thus, by increasing the luminous intensity of the light source module corresponding to one of the detection image frames, the intensity of the light beam reflected by total reflection between the second medium and the liquid to be tested can be increased, thereby increasing the brightness of the second brightness mutation boundary while avoiding saturation of the first brightness mutation boundary and improving the signal-to-noise ratio.

[0067] In the above examples, the refractive index of the liquid to be measured is calculated by forming a brightness mutation boundary on the image caused by total reflection of the liquid to be measured in the refractometer, and the refractive index of the liquid to be measured is corrected by providing a second medium to induce the light beam to generate total reflection to form a brightness mutation boundary on the image. Optionally, the refractometer can also be provided with at least one additional medium to induce the light beam to generate total reflection to form at least one additional brightness mutation boundary on the image for correcting the refractive index of the liquid to be measured. For example, in Figure 9In the illustrated embodiment, at least a third medium, a second medium, and a detection zone are arranged side by side on the surface of the first medium. The third medium is configured to receive a third light beam from the light source module and induce total reflection of the third light beam, thereby forming a new brightness abrupt change boundary corresponding to the third medium on the image. In another example, at least a third medium is arranged in a stacked manner with the first medium, the second medium, and the detection zone. The third medium is configured to induce total reflection of the light beam upon incident on the third medium or upon incident from the third medium to another adjacent medium, thereby forming a new brightness abrupt change boundary corresponding to the third medium on the image.

[0068] When correcting the refractive index of the liquid to be measured, the stronger the correlation between the temperature-dependent characteristics of the refractive index of the medium used for calibration and the temperature-dependent characteristics of the refractive index of the liquid to be measured, the higher the accuracy of the refractive index correction of the liquid to be measured. By setting two or more media for correcting the refractive index of the liquid to be measured, a medium that is more relevant to the characteristics of the liquid to be measured can be selected when correcting the refractive index of the liquid to be measured, thereby improving the accuracy of the refractive index correction of the liquid to be measured. In the example of setting two or more media for correcting the refractive index of the liquid to be measured, when selecting one of the brightness mutation boundaries corresponding to the two or more media in the image to correct the refractive index of the liquid to be measured, a brightness mutation boundary closest to the brightness mutation boundary corresponding to the liquid to be measured can be selected, or a new brightness mutation boundary can be fitted based on the brightness mutation boundaries corresponding to the two or more media for correction, or a machine learning method can be used to select or generate the brightness mutation boundary for correction.

[0069] There are many ways for the processor to determine the position of the brightness mutation boundary in the detection image. For example, the processor can calculate the brightness gradient change of each pixel row in the reflective area of ​​the detection image respectively, and determine the pixel point with the largest gradient change in each row of pixels as the point on the brightness mutation boundary. Alternatively, the processor can also obtain the position of the brightness mutation boundary through edge detection, template matching, machine learning and other methods. Optionally, in the process of obtaining the position of the brightness mutation boundary, the processor can also obtain the current temperature and / or the boundary deviation caused by the assembly tolerance, and compensate the obtained position of the brightness mutation boundary according to the current temperature and / or boundary deviation. After determining the brightness mutation boundary, the processor can look up the corresponding refractive index in a pre-calibrated table of correspondence between brightness mutation boundaries and refractive indices.

[0070] The processor determines the first brightness mutation boundary and the second brightness mutation boundary from the detection image, calculates the refractive index of the liquid to be tested based on the position of the second brightness mutation boundary, and corrects the refractive index of the liquid to be tested based on the position of the first brightness mutation boundary. There are many ways to correct the refractive index of the liquid to be tested based on the position of the first brightness mutation boundary. For example, the processor stores a relationship function between the distance and drift compensation between the first brightness mutation boundary and the second brightness mutation boundary corresponding to the liquid to be tested. The relationship function can be used to determine the drift distance used to compensate for the second brightness mutation boundary, so that the second brightness mutation boundary returns to a position at a fixed temperature (for example, 20°C). Alternatively, other methods, such as machine learning methods, can be used to correct the refractive index of the liquid to be tested based on the position of the first brightness mutation boundary.

[0071] In one example, the photosensitive array can be a complementary metal oxide semiconductor (CMOS) sensor array. Of course, the photosensitive array can also be implemented using other photoelectric sensors such as CCD image sensors. Optionally, after the photosensitive array outputs a detection image, the processor calculates the brightness of the detection image based on the detection image, and only calculates the refractive index based on the detection image when the brightness of the detection image meets a preset condition. There can be multiple preset conditions, for example, the preset condition includes the absolute value of the difference between the brightness of the detection image and the preset target brightness being greater than a threshold.

[0072] Compared to the prior art use of linear arrays as photosensitive arrays, the use of CMOS sensor arrays not only significantly reduces installation requirements but also, leveraging the properties of two-dimensional arrays, enables numerous capabilities previously unattainable with one-dimensional arrays. For example, before calculating the refractive index based on a frame of detection image captured by the photosensitive array, the processor can filter noise based on the pixel values ​​measured by the corresponding rows of sensors on the photosensitive array within the frame of detection image, thereby improving the signal-to-noise ratio. The processor can filter noise on the detection image in the spatial domain or the transform domain. During noise filtering, the processor can perform noise filtering using a windowed sliding average filter, where the width of the filter window can be a value between 1 and the width of the detection image, and the height can be a value between 1 and the height of the detection image. In one specific example, the processor can perform weighted processing (e.g., averaging) on ​​the pixel values ​​detected by the multiple rows of sensors to obtain a noise-filtered result, and then calculate the refractive index of the medium to be inspected based on this noise-filtered result. Of course, the processor can also employ other noise filtering methods, such as machine learning, to filter noise from the detection image frame.

[0073] like Figure 18 As shown, Figure 18The left side shows the pixel value curve for a single row of pixels in the image formed by the light beam received by the photosensitive area array. The right side shows the pixel value curve obtained by averaging the pixel values ​​of this row and the pixel values ​​of the rows above and below it. It can be seen that averaging multiple rows of pixel values ​​can reduce the impact of noise. Compared to the existing technology that only shows a single row of pixel values ​​(i.e., only the detection results of the linear array sensor), the use of the photosensitive area array in this application can increase measurement accuracy.

[0074] For another example, when calculating the refractive index of the medium to be measured based on multiple rows of pixel values ​​in the reflection area of ​​the detection image, the processor can eliminate one or more rows of pixel values ​​affected by stray light, or reduce the influence weight of the row or more rows of pixel values ​​affected by stray light.

[0075] A row of measurement results that is less affected by stray light can be selected from a frame of detection image to calculate the refractive index of the medium to be measured. Stray light is interference light caused by surface wear, dirt, fog condensation, or device position offset in the optical system. The presence of stray light will reduce the accuracy of refractive index calculation. By using a photosensitive array, the processor can determine the pixel rows affected by stray light by comparing and analyzing the brightness of multiple rows of pixel rows. Compared with the linear sensor in the prior art, the use of a photosensitive array in this application can improve the accuracy of refractive index measurement. Optionally, the processor can also determine the pixel rows affected by stray light by comparing and analyzing multiple frames of detection images. This is more robust for refractive index measurement when there is stray light.

[0076] In one example, the processor may further perform noise filtering on multiple detection image frames before calculating the refractive index. For example, after the photosensitive array captures multiple detection image frames, the processor may perform a weighted summation process on these multiple detection image frames to synthesize a single detection image frame, and then use this synthesized detection image to calculate the refractive index. Optionally, before calculating the refractive index, the processor may further perform noise filtering on this synthesized detection image using the single-frame noise filtering method described above.

[0077] In one example, the control module can also obtain brightness information of the current measurement environment and adjust the image quality of the detection image of the photosensitive array based on this brightness information to obtain a better measurement quality. The control module can adjust at least one of the following based on this brightness information: the output light intensity of the light source module, the exposure duration of the photosensitive array, the analog gain of the photosensitive array, and the digital gain of the photosensitive array. The photosensitive array can be used to measure ambient light during time periods other than those used to measure total reflected light, or the detection module can be equipped with other sensors for measuring brightness information of the current environment.

[0078] In one example, a first temperature sensor and a second temperature sensor are provided in the refractometer, wherein the first temperature sensor is used to measure the temperature of the second medium, and the second temperature sensor is provided on the detection area to measure the temperature of the liquid to be measured. Alternatively, the first temperature sensor and the second temperature sensor may not be in direct contact with the second medium or the liquid to be measured, but may be in contact through a material with good thermal conductivity as a medium. Optionally, the first temperature sensor may be mounted on the surface of a prism, and the processor is further used to calculate the temperature of the second medium based on the temperature of the prism surface measured by the first temperature sensor. In actual process, it is difficult to fix the first temperature sensor on the surface of the second medium. The process difficulty can be reduced by installing it on the surface of the prism, and then the temperature of the second medium is calculated based on the measured temperature of the prism surface and a preset model.

[0079] The processor is also configured to obtain measurement results from the first and second temperature sensors to further calibrate the refractive index of the liquid to be measured. Since the refractive index of a liquid is related to its temperature, and the temperature of the prism determines the ratio of its thermal expansion and contraction, and the temperature of the prism can cause a shift in the incident and exit angles of the light beam, a pre-established relationship model between the temperature of the liquid to be measured, the temperature of the reflective module, and the refractive index of the liquid to be measured is used to calculate the refractive index of the liquid to be measured based on the obtained temperature of the liquid to be measured, the temperature of the reflective module, and this relationship model, thereby improving the accuracy of the refractive index calculation.

[0080] For example, in an application scenario where the temperature difference between the second medium of the refractometer and the liquid to be measured is small, the temperature deviation can be calculated by the first temperature sensor and the second temperature sensor. When the position of the second brightness mutation boundary is used to correct the position of the first brightness mutation boundary, the temperature deviation can be introduced to more accurately correct the measurement result of the liquid to be measured. Alternatively, in an application scenario where the temperature difference between the second medium of the refractometer and the liquid to be measured is large (for example, a scenario where a high-temperature liquid to be measured is measured at room temperature), when measuring the liquid to be measured, the temperature conduction is relatively slow due to the large temperature difference. By setting two temperature sensors, the two temperatures can be measured more accurately, and then the temperature of the second medium and the liquid to be measured when they reach thermal equilibrium can be calculated. Alternatively, further, the temperature change trend of the second medium and the liquid to be measured can be obtained based on the temperatures measured by the two temperature sensors, and the temperature change of the second medium and the liquid to be measured can be more accurately predicted by a preset temperature change model, and the measurement result of the liquid to be measured can be corrected in combination with the temperature change.

[0081] In one example, the processor can also calculate the turbidity of the liquid to be tested based on the detection image output by the photosensitive array. In the output light of the light source module, the light beam transmitted from the reflection module to the liquid to be tested will be scattered when it encounters suspended particles in the liquid to be tested. Part of the scattered light will pass through the reflection module and then be incident on the photosensitive array. Scattering is divided into Rayleigh scattering, Mie scattering and refraction with different angular components according to the size of the scattered particles. By analyzing the detection image detected by the photosensitive array, the processor can obtain the light intensity distribution of the detection image, and obtain the size and properties of the scattered particles based on the light intensity distribution, and then determine the turbidity of the liquid.

[0082] For example, Figure 8 As shown in FIG, the scattering caused by particles in the liquid will cause brightness values ​​to appear in non-reflective areas where brightness should not appear. Therefore, the processor can calculate the particle concentration of the liquid based on the brightness of the non-reflective areas. Specifically, since different pixel positions in the detection image correspond to light beams incident at different angles on the total reflection interface, the non-reflective areas in the detection image can be understood to include total reflection areas and non-total reflection areas. Figure 8 The total reflection area of ​​the non-reflection area is located above and below the total reflection area of ​​the reflective area, and the non-total reflection area of ​​the non-reflection area is located above and below the non-total reflection area of ​​the reflective area. Since the light beam scattered by the particles in the liquid to be measured can only re-enter the reflection module at an angle within the total reflection angle, the detection image formed by the photosensitive array only shows scattered light spots in the area corresponding to the angle less than the total reflection angle. In other words, the scattered light beam will only appear in the non-total reflection area in the detection image.

[0083] Therefore, in one example, the processor can calculate the scattered brightness based on the brightness of the non-totally reflective region within the non-reflective region on the detected image. Alternatively, the processor can use the brightness of the fully reflective region within the non-reflective region as a reference value to calculate the absolute value of the scattered brightness. For example, the processor can subtract the brightness of the fully reflective region within the non-reflective region from the brightness of the non-totally reflective region within the non-reflective region on the detected image to obtain the absolute value of the scattered brightness. After obtaining the scattered brightness, the processor can determine the corresponding turbidity of the liquid to be tested based on a pre-established model for the correspondence between scattered brightness and liquid turbidity.

[0084] Optionally, when determining the brightness of a fully reflective region within a non-reflective region, the processor may perform a weighted average of the brightness of at least some of the pixels in that region to obtain the brightness of the fully reflective region. Similarly, when determining the brightness of a non-fully reflective region within a non-reflective region, the processor may perform a weighted average of the brightness of at least some of the pixels in that region to obtain the brightness of the non-fully reflective region. This can reduce calculation errors.

[0085] For example, Figure 8 As shown, scattering caused by particles near the total reflection interface of the reflective module can blur the brightness mutation boundary in the reflective area of ​​the detected image. Therefore, the processor can also obtain the degree of blur of the brightness mutation boundary in the detection image detected by the photosensitive area array and determine the turbidity of the liquid under test based on this blur. The processor can use a pre-calibrated table to look up the corresponding relationship between the blur of the brightness mutation boundary and the turbidity of the liquid to obtain the corresponding turbidity of the liquid under test.

[0086] In some examples, the processor is configured to calculate the turbidity of the liquid based on the brightness of a non-reflective area in a detected image when the concentration of the liquid to be tested is lower than a preset concentration, and to calculate the turbidity of the liquid based on the blurriness of a brightness mutation boundary in the detected image when the concentration of the liquid to be tested is higher than the preset concentration. When the concentration of the liquid to be tested is low, the turbidity of the liquid to be tested and the brightness of the non-reflective area in the detected image have a good linear relationship, and calculating the turbidity based on the brightness of the non-reflective area can have a higher accuracy rate. When the concentration of the liquid to be tested is high, this linear relationship decreases, and calculating the turbidity based on the blurriness of the brightness mutation boundary can be more accurate.

[0087] Calculating turbidity using a refractometer has many applications. In some examples, a refractometer can be used to detect the composition of liquids. For example, a refractometer can simultaneously measure the refractive index and turbidity of a liquid to determine its properties. In another example, a refractometer can simultaneously measure the refractive index and turbidity of a liquid (such as coffee) to determine its sugar and milk content. In another example, a refractometer can simultaneously measure the refractive index and turbidity of a liquid (such as juice) to determine its sugar and pulp content. In another example, a refractometer can measure the refractive index and turbidity of clear liquid in a sensor. These refractive index and turbidity values ​​can be used to determine whether the sensor is contaminated. Optionally, this contamination determination result can be used to determine whether further cleaning is necessary. In one application scenario, a refractometer can be used in cleaning machines (such as dishwashers and washing machines) to detect the refractive index and turbidity of the liquid after cleaning an object to determine the cleanliness of the cleaned object. In another application scenario, a refractometer can be used to test water quality. The refractometer's determination results can be displayed to the user through an interactive module.

[0088] Because changes in the turbidity of the liquid under test also affect the refractive index of the liquid under test, in some examples, the processor is further configured to, after calculating the turbidity of the liquid under test, correct the refractive index of the liquid under test based on the pre-calibrated relationship between turbidity and refractive index. For example, in one application scenario, when a refractometer measures both the turbidity and sugar content of the liquid under test, the simultaneous measurement of the turbidity and sugar content of the liquid under test can distinguish the ratio of milk and sugar in the liquid under test, thereby obtaining accurate milk content and sugar content values, and then more accurately calculating the calorie content of the liquid under test.

[0089] In one example, the refractometer also has a standby mode and / or a low-power mode. In the standby mode, the control module is in a dormant standby state, the light source module and the photosensitive array are both powered off, and the overall power consumption of the refractometer is at the uW level. In the low-power mode, the control module is used to control the light source module and the photosensitive array to flash synchronously, with an extremely short power-on time, and the overall power consumption of the refractometer is at the mW level. Specifically, when controlling the light source module 1 and the photosensitive array, the control module can synchronously trigger a pulse width modulation (PWM) signal according to the frame signal of the photosensitive array to dim the light source module.

[0090] In some examples, the refractometer also includes at least one of the following: a colorimeter for detecting the color of the liquid to be tested, an impedance meter for detecting the content of ions (such as acidic ions) in the liquid to be tested, and a pH meter for detecting the acidity value of the liquid to be tested, so that the processor can assist in determining the type of the liquid to be tested based on this information.

[0091] In one example, the refractometer further includes a wireless communication module for transmitting at least one of the refractive index, turbidity, and temperature of the liquid under test obtained by the processor to another client (e.g., a mobile app, an application, a computer client, a server, etc.), so that the client can display or analyze the data collected from one or more refractometers. In another example, the refractometer further includes an interaction module for displaying the detected data to a user.

[0092] The present application also provides a detection device, which is provided with the above-mentioned refractometer. For example, the detection container is a smart cup. Figure 19 As shown, Figure 19 This is a schematic diagram of the structure of a smart cup. The smart cup includes a cup body and the above-mentioned refractometer 201 arranged in the cup body, which is used to detect the refractive index and / or turbidity of the liquid in the cup. Figure 19 As shown, the refractometer 201 is arranged at the bottom of the cup body 200. Alternatively, optionally, the refractometer is fixed to the cup lid in the cup body, which can be easily installed. When it is necessary to measure the refractive index of the liquid, the user only needs to turn the water cup with the lid upside down to immediately perform the measurement. The refractometer can be an independent module fixed in the cup body of the smart cup. In this way, the refractometer and the cup body of the smart cup can be independently assembled, which is simpler in structure and waterproofing process. Alternatively, the refractometer can be integrated in the cup body of the smart cup. Optionally, in the above-mentioned example where the refractometer includes a waterproof part, the refractometer can be embedded in the inside of the glass, and the cup wall is used as the waterproof part of the refractometer.

[0093] Optionally, the smart cup is further equipped with a micro-pressure sensor and a calculation module. The micro-pressure sensor is used to detect the volume of the liquid in the cup, and the calculation module is used to calculate the calorie content of the liquid in the cup based on the refractive index and / or turbidity of the liquid measured by a refractometer. Optionally, the micro-pressure sensor is located in the enclosed space formed between the bottom of the cup body and a diaphragm disposed above the bottom.

[0094] For another example, the detection device is a smart scale. Figure 20 As shown, Figure 20 It is a structural diagram of a smart scale. The smart scale includes a scale body 210 and the above-mentioned refractometer 211 arranged in the scale body 210. The surface of the scale body 210 is also provided with a liquid containing area 212 and a first display area (not shown in the figure). The refractometer 211 is used to detect the refractive index of the liquid in the liquid containing area 212, and the first display area is used to display the refractive index of the liquid. Optionally, the surface of the smart scale is also provided with a weighing area 213 and a second display area (not shown in the figure). The second display area is used to display the weight of the object on the weighing area. Optionally, the weighing area 213 and the liquid containing area 212 are arranged side by side on the surface of the smart scale. Optionally, the first display area and the second display area are provided separately or combined.

[0095] For another example, the detection device is an intelligent animal urine detector (pad, etc.), which is equipped with the above-mentioned refractometer and measures the refractive index of animal urine through the refractometer.

[0096] The present application also provides a method for detecting the refractive index of a liquid to be tested using a refractometer. Figure 21 As shown, Figure 21 This is a schematic diagram of an embodiment of a method for detecting the refractive index of a liquid to be tested using a refractometer in the present application. The method includes the following steps: S2201, emitting a light beam to a reflection module in the refractometer. S2202, converging the light beam that is at least totally reflected by the reflection module to a photosensitive array located on the focal plane of the converging module through a converging module. S2203, imaging the received light beam using the photosensitive array to generate a detection image. S2204, determining a brightness mutation boundary in the detection image based on the detection image. S2205, determining a corresponding total reflection angle based on the position of the brightness mutation boundary in the detection image. S2206, determining the refractive index of the medium corresponding to the brightness mutation boundary based on the total reflection angle.

[0097] In one example, the refractometer further includes a detection area disposed on a surface of a medium in the reflection module. When the detection area is covered with a liquid to be measured and the refractive index of the liquid to be measured is lower than the refractive index of the first medium, at least a portion of the light beam is totally reflected by the liquid to be measured; and only one brightness mutation boundary corresponding to the refractive index of the liquid to be measured is formed in the detection image.

[0098] In one example, the light beam includes a first light beam and a second light beam, the reflection module includes a first medium and a second medium arranged adjacent to each other, the refractive index of the first medium is greater than the refractive index of the second medium, the first light beam is incident from the first medium to the second medium, and is at least partially totally reflected by the second medium; the refractometer also includes a detection area, which is arranged on the surface of one of the media in the reflection module, for receiving the second light beam; when the detection area is covered with a liquid to be tested, and the refractive index of the liquid to be tested is lower than the refractive index of one of the media, at least part of the second light beam is totally reflected by the liquid to be tested; a first brightness mutation boundary corresponding to the second medium and a second brightness mutation boundary corresponding to the liquid to be tested are formed in the detection image, and the method also includes: calculating the refractive index of the liquid to be tested based on the position of the second brightness mutation boundary, and correcting the refractive index of the liquid to be tested based on the position of the first brightness mutation boundary.

[0099] In one example, the detection area and the second medium are located in different areas on the same surface of the first medium, and the second light beam is incident from the first medium to the detection area without passing through the second medium.

[0100] In one example, the reflection module also includes a third medium having a refractive index different from that of the second medium, which is located in different areas on the same surface of the first medium as the detection area and the second medium; the light beam also includes a third light beam, which is at least partially totally reflected when incident from the first medium to the third medium, and a third brightness mutation boundary corresponding to the third medium is also formed in the detection image; the correction of the refractive index of the liquid to be tested according to the position of the first brightness mutation boundary includes: correcting the refractive index of the liquid to be tested according to the first brightness mutation boundary and / or the third brightness mutation boundary.

[0101] In one example, the first medium includes a prism having a light incident surface, a light exit surface, and a detection surface, and the detection area and the second medium are respectively located on different areas of the detection surface; the method further includes: allowing at least a portion of the light beam that is totally reflected by the second medium to be incident on the converging lens through the first light exit through the first light exit, and allowing at least a portion of the light beam that is totally reflected by the liquid to be measured to be incident on the converging lens through the second light exit. In one example, a light inlet is further provided on the light incident surface, and the first light beam and the second light beam are incident on the detection surface through the light inlet; wherein the first light exit and the second light exit are respectively located on both sides of the projection of the light inlet on the light exit surface, and do not overlap with the projection.

[0102] In one example, the first medium, the second medium, and the detection area are stacked, and the detection area is arranged on a side of the second medium facing away from the first medium. The second light beam passes through the first medium and the second medium in sequence.

[0103] In one example, the reflection module includes a prism having a light incident surface, a light exit surface, and a detection surface, and the detection area is located on the detection surface; and a cured material layer and a transparent glass layer are sandwiched between the detection area and the detection surface, and the transparent glass layer is used to seal the material layer and the prism in the refractometer, and the detection area is located on the side of the transparent glass layer facing away from the material layer.

[0104] In one example, the refractive index of the prism is greater than the refractive index of the material layer, and the refractive index of the material layer is greater than the refractive index of the transparent glass layer. When the refractive index of the liquid to be measured is less than the refractive index of the transparent glass layer, at least three brightness mutation dividing lines are formed on the detection image; the first medium is the prism, and the second medium is the material layer; or, the first medium is the material layer, and the second medium is the transparent glass layer.

[0105] In one example, the refractive index of the prism is greater than the refractive index of the material layer, the refractive index of the material layer is greater than the refractive index of the transparent glass layer, and the photosensitive array avoids the position where the light beam totally reflected by the material layer converges through the converging lens, so that only two brightness mutation dividing lines are formed on the detection image; the first medium is the material layer, and the second medium is the transparent glass layer.

[0106] In one example, the refractive index of the prism is greater than the refractive index of the material layer, the refractive index of the material layer is less than or equal to the refractive index of the light-transmitting glass layer, the first medium is the prism, and the second medium is the material layer, or the refractive index of the prism is less than or equal to the refractive index of the material layer, and the refractive index of the material layer is greater than the refractive index of the light-transmitting glass layer.

[0107] In one example, the cured material layer is a light-cured coating, a high-temperature-cured coating, or a naturally-cured coating. In one example, the cured material layer is a light-cured shadowless adhesive layer. In one example, the refractive index of the cured material layer is greater than 1.33 and not greater than 1.6, and the value of the refractive index changing with temperature is within a range of -0.0003 / deg C to 0.0003 / deg C. In one example, the refractive index of the second medium is greater than 1.33 and not greater than 1.6, and the value of the refractive index changing with temperature is within a range of -0.0003 / deg C to 0.0003 / deg C.

[0108] In one example, the method of imaging the received light beam using the photosensitive array to generate a detection image includes: generating a detection image sequence, wherein at least some of the images in the detection image sequence use different exposure parameters; or, at least some of the images in the detection image sequence correspond to different luminous intensities of the light source modules.

[0109] In one example, the aperture of the light-emitting surface of the light source module is the same as the aperture of the light-transmitting aperture of the convergence module or the difference is less than 1 / 5 of the aperture of the light-emitting surface, or the aperture of the light-emitting surface of the light source module is greater than 2 times the aperture of the light-transmitting aperture of the convergence module. In one example, the detection angle range of the photosensitive surface array covers the total reflection angle range of the convergence module. In one example, the half-width at half-maximum of the output light of the light source module is less than 5nm, or a narrow-band filter is provided on the output light path of the light source module, and the half-width at half-maximum of the output light after filtering by the narrow-band filter is less than 5nm. In one example, a light homogenizer is provided on the output light path of the light source module. In one example, the output light of the light source module is in the green light band, and the photosensitive surface array is a CMOS sensor using an RGGB Bell pattern.

[0110] In one example, before determining the brightness mutation boundary in the detected image based on the detected image, the method further includes: determining whether the absolute value of the difference between the brightness of the detected image and a preset brightness is greater than a threshold. In one example, before determining the brightness mutation boundary in the detected image based on the detected image, the method further includes: performing noise filtering on the target pixel row based on at least a portion of the pixel rows above and below the target pixel row in the detected image. In one example, performing noise filtering on the target pixel row based on at least a portion of the pixel rows above and below the target pixel row in the detected image includes: using a weighted average of the pixel values ​​of the target pixel row and the pixel values ​​of at least a portion of the pixel rows as the pixel value after noise filtering of the target pixel row. In one example, before determining the brightness mutation boundary in the detected image based on the detected image, the method further includes: determining pixel rows in the detected image affected by stray light, wherein the pixel rows affected by stray light are not used to determine the refractive index of the medium located on the side of the total reflection interface facing away from the light source module. In one example, the detected image is obtained by performing a weighted summation of multiple frames of images acquired by the photosensitive area array.

[0111] In one example, the method further includes: obtaining the temperature of the medium located outside the total reflection interface and the temperature of the total reflection interface; calculating the refractive index of the medium based on a pre-stored relationship model between the temperature of the medium to be measured, the temperature of the total reflection interface and the refractive index of the medium to be measured, and the obtained temperature of the medium located outside the total reflection interface and the temperature of the total reflection interface.

[0112] In one example, the method further includes: calculating the turbidity of the medium outside the reflective module based on the detected image. In one example, the detected image includes a non-reflective area; calculating the turbidity of the medium outside the reflective module based on the detected image includes: obtaining the scattered brightness of a non-total reflection area within the non-reflective area and / or the blurriness of the brightness mutation boundary; wherein the non-total reflection area within the non-reflective area corresponds to an area within the non-reflective area that is incident on the reflective module at an angle less than total reflection and then enters the photosensitive array; and calculating the turbidity based on the scattered brightness of the non-total reflection area within the non-reflective area and / or the blurriness of the brightness mutation boundary.

[0113] In one example, the non-reflective area further includes a total reflection area located on one side of the non-totally reflective area; and obtaining the scattered brightness of the non-totally reflective area in the non-reflective area includes: calculating the scattered brightness of the non-totally reflective area in the non-reflective area in the detection image using the brightness of the total reflection area in the non-reflective area as a reference value. In one example, calculating the turbidity based on the scattered brightness of the non-totally reflective area in the non-reflective area and / or the blurriness of the brightness mutation boundary in the non-reflective area includes: calculating the turbidity of the liquid to be tested based on the scattered brightness of the non-totally reflective area in the non-reflective area in the detection image when the concentration of the liquid to be tested is lower than a preset concentration; and calculating the turbidity of the liquid to be tested based on the blurriness of the brightness mutation boundary in the detection image when the concentration of the liquid to be tested is higher than a preset concentration.

[0114] In one example, the medium outside the reflective module is a liquid to be tested; the method further includes: obtaining the volume of the liquid to be tested; and calculating the calories of the liquid to be tested based on the refractive index, turbidity, and volume of the liquid to be tested. In one example, the medium outside the reflective module is a liquid to be tested; the method further includes: obtaining auxiliary information using an auxiliary device, wherein the auxiliary device includes a colorimeter, and the auxiliary information includes the color of the liquid to be tested; or, the auxiliary device includes an impedance meter, and the auxiliary information includes the ion content of the liquid to be tested; or, the auxiliary device includes a pH meter, and the auxiliary information includes the acidity value of the liquid to be tested; and determining the type of the liquid to be tested based on the auxiliary information and the refractive index and / or turbidity of the liquid to be tested.

[0115] In one example, before emitting a light beam toward the reflective module within the refractometer, the method further includes: emitting a liquid to clean the target object, wherein the medium located outside the reflective module is the liquid after cleaning the target object. The method further includes: determining the cleanliness of the target object based on the refractive index of the liquid after cleaning the target object. In another example, the method further includes: determining whether further cleaning of the target object is required based on the cleanliness of the target object.

[0116] In one example, before emitting a light beam toward the reflective module within the refractometer, the method further includes: securing the refractometer to the inner wall of a pipe; wherein the refractometer is used to measure the refractive index of the liquid flowing within the pipe, and the brightness mutation boundary includes a brightness mutation boundary corresponding to the liquid flowing within the pipe. Because the refractometer of the present application can self-calibrate in real time, compared to existing calculation refractometers that require calibration before measuring liquid, the refractometer of the present application can obtain more accurate measurement results when measuring liquid flowing in a pipe.

[0117] Although the present invention has been particularly shown and described in conjunction with preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made to the present invention without departing from the spirit and scope of the invention as defined in the appended claims, and all such changes are within the scope of protection of the present invention.

Claims

1. A refractometer, characterized in that: It includes a light source module, a reflection module, a lens module, a photosensitive array, a control module and a processor; The control module is used to control the light beam emitted by the light source module; The reflection module is used to receive the light beam from the light source module. When the light beam from the light source module meets the total reflection condition in the reflection module, the light beam is totally reflected in the reflection module and incident on the lens module. The reflection module includes at least two media, which are a first medium and a second medium arranged adjacent to each other, and the refractive index of the first medium is greater than the refractive index of the second medium. In the outgoing light beam, part of the light beam incident from the first medium to the second medium is totally reflected by the second medium to the lens module. The refractometer also includes a detection area, which is arranged on the surface of one of the media in the reflection module. When the detection area is covered with a liquid to be measured, part of the light beam in the outgoing light beam incident on the liquid to be measured is totally reflected by the liquid to be measured to the lens module. The lens module is used to converge the light beam from the reflection module onto the focal plane of the lens module; The photosensitive array is located on the focal plane of the lens module, and the control module is further used to control the photosensitive array to detect the received light beam and output a detection image; A processor is used to determine, based on the detection image, a first brightness mutation boundary corresponding to the light beam totally reflected by the second medium and a second brightness mutation boundary corresponding to the light beam totally reflected by the liquid to be tested, and to determine the refractive index of the liquid to be tested based on the respective positions of the first brightness mutation boundary and the second brightness mutation boundary.

2. The refractometer according to claim 1, wherein The processor is used to determine the refractive index of the liquid to be tested according to the distance between the first brightness mutation boundary and the second brightness mutation boundary.

3. The refractometer according to claim 1, wherein The detection area is provided on the surface of the first medium and is used to receive the light beam from the first medium; and the detection area and the second medium are respectively located in different areas on the same surface of the first medium.

4. The refractometer according to claim 2, wherein: The reflection module further includes a third medium having a different refractive index from the second medium, and is located in different areas on the same surface of the first medium as the detection area and the second medium. The third medium is used to totally reflect at least a portion of the light beam received from the light source module, and converge the light beam to the photosensitive array through the lens module, thereby forming a corresponding third brightness mutation boundary in the detected image. The processor is used to correct the refractive index of the liquid to be tested according to the first brightness mutation boundary and / or the third brightness mutation boundary.

5. The refractometer according to claim 3, wherein: The first medium includes a prism having a light incident surface, a light exit surface, and a detection surface, and the detection area and the second medium are respectively located on different areas of the detection surface; The light emitting surface is provided with a first light outlet and a second light outlet corresponding to the second medium and the detection area respectively. At least part of the light beam totally reflected by the second medium is incident on the lens through the first light outlet, and at least part of the light beam totally reflected by the liquid to be measured is incident on the lens through the second light outlet.

6. The refractometer according to claim 5, characterized in that The light incident surface is further provided with a light entrance, and at least a portion of the outgoing light beam is incident on the detection surface through the light entrance; The first light outlet and the second light outlet are respectively located on two sides of a projection of the light entrance on the light exit surface, and do not overlap with the projection.

7. The refractometer according to claim 1, wherein The first medium, the second medium and the detection area are stacked, and the detection area is arranged on a side of the second medium facing away from the first medium, for receiving a portion of the outgoing light beam that passes through the first medium and the second medium in sequence.

8. The refractometer according to claim 7, wherein: The reflection module includes a prism having a light incident surface, a light exit surface and a detection surface. The detection area is located on the detection surface, and a cured material layer and a transparent glass layer are sandwiched between the detection area and the detection surface. The transparent glass layer is used to seal the material layer and the prism in the refractometer. The detection area is located on the side of the transparent glass layer facing away from the material layer.

9. The refractometer according to claim 8, wherein The refractive index of the prism is greater than the refractive index of the material layer, and the refractive index of the material layer is greater than the refractive index of the light-transmitting glass layer. When the refractive index of the liquid to be measured is less than the refractive index of the light-transmitting glass layer, at least three brightness mutation boundary lines are formed on the detection image. The first medium is the prism, and the second medium is the material layer; or the first medium is the material layer, and the second medium is the light-transmitting glass layer.

10. The refractometer according to claim 8, wherein The refractive index of the prism is greater than that of the material layer, which is greater than that of the light-transmitting glass layer, and the photosensitive array avoids the position where the light beams totally reflected by the material layer converge through the lens, so that two brightness mutation dividing lines are formed on the detection image; The first medium is the material layer, and the second medium is the light-transmitting glass layer.

11. The refractometer according to claim 8, wherein The refractive index of the prism is greater than the refractive index of the material layer, the refractive index of the material layer is less than or equal to the refractive index of the light-transmitting glass layer, the first medium is the prism, and the second medium is the material layer, or, The refractive index of the prism is less than or equal to the refractive index of the material layer, and the refractive index of the material layer is greater than the refractive index of the light-transmitting glass layer.

12. The refractometer according to claim 8, wherein The cured material layer is a light-cured coating, a high-temperature-cured coating, or a naturally-cured coating.

13. The refractometer according to claim 8, wherein the cured material layer is a light-cured shadowless adhesive layer. The refractometer according to claim 8 , wherein the refractive index of the light-transmitting glass layer is greater than a maximum value of a refractive index measurement range of the refractometer.

15. The refractometer according to claim 1, wherein The refractive index of the second medium is greater than 1.33 and not greater than 1.6, and the value of the refractive index changing with temperature is within a range of -0.0003 / deg C to 0.0003 / deg C.

16. The refractometer according to claim 1, wherein The detection image includes a first edge and a second edge opposite to each other, wherein the closer the brightness mutation boundary in the detection image is to the first edge, the higher the corresponding refractive index; The first brightness mutation boundary is located between the first edge in the detection image and the brightness mutation boundary corresponding to the maximum refractive index in the refractive index measurement range of the refractometer.

17. The refractometer according to claim 1, wherein The photosensitive array is used to output a detection image sequence, wherein at least some images in the detection image sequence have different exposure parameters; or The light source modules respectively correspond to different luminous intensities of at least a portion of images in the detection image sequence.

18. The refractometer according to any one of claims 1 to 17, characterized in that The aperture of the light-emitting surface of the light source module is the same as the aperture of the lens module or the difference between them is less than 1 / 5 of the aperture of the light-emitting surface. Alternatively, the aperture of the light-emitting surface of the light source module is greater than twice the light-transmitting aperture of the lens module.

19. The refractometer according to any one of claims 1 to 17, wherein: The detection angle range of the photosensitive array covers the total reflection angle range of the lens module.

20. The refractometer according to any one of claims 1 to 17, wherein: The half-maximum width of the output light of the light source module is less than 5 nm, or a narrow-band filter is provided on the output light path of the light source module, and the half-maximum width of the output light after filtering by the narrow-band filter is less than 5 nm.

21. The refractometer according to any one of claims 1 to 17, wherein: A light homogenizer is provided on the outgoing light path of the light source module.

22. The refractometer according to any one of claims 1 to 17, wherein: The light emitted by the light source module is in the green light band, and the photosensitive array is a CMOS sensor with a Bell pattern of RGGB.

23. The refractometer according to any one of claims 1 to 17, wherein: The processor is further configured to determine whether an absolute value of a difference between the brightness of the detection image and a preset brightness is greater than a threshold before determining a brightness mutation boundary in the detection image according to the detection image.

24. The refractometer according to any one of claims 1 to 17, wherein: The processor is further configured to filter noise on the target pixel row in the detection image based on at least a portion of pixel rows above and below the target pixel row in the detection image before determining a brightness mutation boundary in the detection image based on the detection image.

25. The refractometer according to claim 24, wherein The processor is configured to take a weighted average of the pixel value of the target pixel row and the pixel values ​​of at least part of the pixel rows as the pixel value of the target pixel row after noise filtering.

26. The refractometer according to any one of claims 1 to 17, wherein: The processor is further configured to determine pixel rows in the detection image that are affected by stray light, wherein the pixel rows affected by stray light are not used to determine the refractive index of a medium located on a side of the total reflection interface facing away from the light source module.

27. The refractometer according to claim 25, wherein The processor is further configured to determine the pixel rows in the detection image affected by stray light based on brightness comparison results of multiple pixel rows and / or brightness comparison results of multiple frames of detection images.

28. The refractometer according to any one of claims 1 to 17, wherein: The detection image is obtained by weighted summing of multiple frames of images acquired by the photosensitive array.

29. The refractometer according to any one of claims 1 to 17, wherein: The processor is further configured to calculate the turbidity of the medium located on a side of the total reflection interface facing away from the light source module based on the detection image.

30. The refractometer according to claim 29, wherein The detected image includes a non-reflective area, and the processor is used to obtain the scattered brightness of the non-total reflection area in the non-reflective area and / or the blurring degree of the brightness mutation boundary, and calculate the turbidity according to the scattered brightness of the non-total reflection area in the non-reflective area and / or the blurring degree of the brightness mutation boundary; The non-total reflection area in the non-reflection area corresponds to an area in the non-reflection area that is incident on the total reflection interface at an angle smaller than the total reflection angle and then incident on the photosensitive array.

31. The refractometer according to claim 30, wherein The non-reflective area further includes a total reflection area located on one side of the non-total reflection area; The processor is configured to calculate the scattered brightness of the non-total reflection area of ​​the non-reflection area in the detection image by taking the brightness of the total reflection area in the non-reflection area as a reference value.

32. The refractometer according to claim 30, wherein The processor is used to calculate the turbidity of the liquid to be tested based on the scattered brightness of the non-total reflection area on the non-reflection area in the detection image when the concentration of the liquid to be tested is lower than the preset concentration; and to calculate the turbidity of the liquid to be tested based on the blurring degree of the brightness mutation boundary on the detection image when the concentration of the liquid to be tested is higher than the preset concentration.

33. The refractometer according to any one of claims 1 to 17, wherein: The refractometer has a standby mode; In the standby mode, the control module is in a dormant standby state, and the light source module and the photosensitive array are in a power-off state.

34. The refractometer according to any one of claims 1 to 17, wherein: The refractometer has a low power mode, In the low power consumption mode, the control module is used to control the light source module and the photosensitive array to strobe synchronously.

35. The refractometer according to claim 34, wherein The control module is used to synchronously trigger a pulse width modulation signal to control the light source module according to the frame signal of the photosensitive array.

36. The refractometer according to any one of claims 1 to 17, wherein: The control module is further configured to obtain brightness information of the current environment and adjust the quality of the detection image of the photosensitive array according to the brightness information.

37. The refractometer according to claim 36, wherein The control module is used to adjust the image quality of the detection image of the photosensitive array by adjusting at least one of the following: The output light intensity of the light source module, the exposure time of the photosensitive array, the analog gain of the photosensitive array, and the digital gain of the photosensitive array.

38. The refractometer according to any one of claims 1 to 17, wherein: The refractometer further includes a first temperature sensor and a second temperature sensor, wherein the first temperature sensor is disposed inside the reflection module or on a surface of the reflection module in an area outside the optical path, and is used to detect the temperature of the reflection module; The second temperature sensor is provided on the surface of the reflective module facing the liquid to be measured, and is used to detect the temperature of the liquid to be measured; The processor pre-stores a relationship model between the temperature of the liquid to be measured, the temperature of the reflection module and the refractive index of the liquid to be measured. The processor is also used to calculate the refractive index of the liquid to be measured based on the temperatures obtained by the first temperature sensor and the second temperature sensor and the relationship model.

39. The refractometer according to any one of claims 1 to 17, wherein: The photosensitive area array is an area array CMOS image sensor.

40. A method for detecting refractive index, characterized in that: include: A light source module is used to emit a light beam toward a reflection module within the refractometer; wherein the reflection module includes at least two media, namely, a first medium and a second medium disposed adjacent to each other, the refractive index of the first medium being greater than the refractive index of the second medium; a portion of the light beam in the emitted light beam that is incident from the first medium to the second medium is totally reflected by the second medium to the lens module; the refractometer further includes a detection area disposed on a surface of one of the media within the reflection module; when the detection area is covered with a liquid to be measured, a portion of the light beam in the emitted light beam that is incident on the liquid to be measured is totally reflected by the liquid to be measured to the lens module; Converging the light beams at least totally reflected by the reflection module onto a photosensitive surface array located on a focal plane of the lens module through the lens module; Imaging the received light beam using the photosensitive array to generate a detection image; Determining, based on the detection image, a first brightness mutation boundary corresponding to the light beam totally reflected by the second medium and a second brightness mutation boundary corresponding to the light beam totally reflected by the liquid to be tested; The refractive index of the liquid to be tested is determined according to the positions of the first brightness mutation boundary line and the second brightness mutation boundary line in the detection image.

41. The method according to claim 40, wherein The determining the refractive index of the liquid to be tested according to the positions of the first brightness mutation boundary and the second brightness mutation boundary in the detection image respectively includes: The refractive index of the liquid to be tested is calculated according to the distance between the first brightness mutation boundary line and the second brightness mutation boundary line.

42. The method according to claim 40, wherein in, The detection area and the second medium are respectively located in different areas on the same surface of the first medium, and a portion of the outgoing light beam is incident on the detection area from the first medium without passing through the second medium.

43. The method according to claim 42, characterized in that The reflection module further includes a third medium having a different refractive index from the second medium, and the third medium and the detection area and the second medium are respectively located in different areas on the same surface of the first medium; When a portion of the outgoing light beam is incident from the first medium to the third medium, at least a portion of the outgoing light beam is totally reflected, and a third brightness mutation boundary corresponding to the third medium is formed in the detection image; The determining the refractive index of the liquid to be tested according to the positions of the first brightness mutation boundary and the second brightness mutation boundary in the detection image respectively includes: Calculating the refractive index of the liquid to be tested according to the position of the second brightness mutation boundary; The refractive index of the liquid to be tested is corrected according to the first brightness mutation boundary and / or the third brightness mutation boundary.

44. The method according to claim 42, wherein The first medium includes a prism having a light incident surface, a light exit surface, and a detection surface, and the detection area and the second medium are respectively located on different areas of the detection surface; The method further comprises: The first light exit port on the light exit surface allows at least part of the light beam totally reflected by the second medium to be incident on the lens through the first light exit port. The second light exit port on the light exit surface allows at least a portion of the light beam totally reflected by the liquid to be measured to be incident on the lens through the second light exit port.

45. The method according to claim 44, wherein the light incident surface is further provided with a light entrance, and at least a portion of the outgoing light beam is incident on the detection surface through the light entrance; in, The first light outlet and the second light outlet are respectively located on two sides of a projection of the light entrance on the light exit surface, and do not overlap with the projection.

46. ​​The method according to claim 40, wherein The first medium, the second medium and the detection area are stacked, and the detection area is arranged on a side of the second medium facing away from the first medium. The second light beam passes through the first medium and the second medium in sequence.

47. The method according to claim 46, wherein The reflection module includes a prism having a light incident surface, a light exit surface and a detection surface, and the detection area is located on the detection surface; and a cured material layer and a transparent glass layer are sandwiched between the detection area and the detection surface, and the transparent glass layer is used to seal the material layer and the prism in the refractometer, and the detection area is located on the side of the transparent glass layer facing away from the material layer.

48. The method according to claim 47, wherein The refractive index of the prism is greater than the refractive index of the material layer, and the refractive index of the material layer is greater than the refractive index of the light-transmitting glass layer. When the refractive index of the liquid to be measured is less than the refractive index of the light-transmitting glass layer, at least three brightness mutation boundary lines are formed on the detection image. The first medium is the prism, and the second medium is the material layer; or the first medium is the material layer, and the second medium is the light-transmitting glass layer.

49. The method according to claim 47, wherein The refractive index of the prism is greater than that of the material layer, which is greater than that of the light-transmitting glass layer, and the photosensitive array avoids the position where the light beams totally reflected by the material layer converge through the lens, so that only two brightness mutation dividing lines are formed on the detection image; The first medium is the material layer, and the second medium is the light-transmitting glass layer.

50. The method according to claim 47, wherein The refractive index of the prism is greater than the refractive index of the material layer, the refractive index of the material layer is less than or equal to the refractive index of the light-transmitting glass layer, the first medium is the prism, and the second medium is the material layer, or, The refractive index of the prism is less than or equal to the refractive index of the material layer, and the refractive index of the material layer is greater than the refractive index of the light-transmitting glass layer.

51. The method according to claim 47, wherein The cured material layer is a light-cured coating, a high-temperature-cured coating, or a naturally-cured coating.

52. The method of claim 47, wherein the cured material layer is a light-cured shadowless adhesive layer.

53. The method according to claim 47, wherein the refractive index of the light-transmitting glass layer is greater than the maximum value of the refractive index measurement range of the refractometer.

54. The method according to claim 40, wherein The refractive index of the second medium is greater than 1.33 and not greater than 1.6, and the value of the refractive index changing with temperature is within a range of -0.0003 / deg C to 0.0003 / deg C.

55. The method according to claim 40, wherein The detection image includes a first edge and a second edge opposite to each other, wherein the closer the brightness mutation boundary in the detection image is to the first edge, the higher the corresponding refractive index; The first brightness mutation boundary is located between the first edge in the detection image and the brightness mutation boundary corresponding to the maximum refractive index in the refractive index measurement range of the refractometer.

56. The method according to claim 40, wherein The light beam is emitted by the light source module, and the light beam is imaged by the photosensitive array to generate a detection image, including: A detection image sequence is generated, wherein at least some of the images in the detection image sequence use different exposure parameters; or at least some of the images in the detection image sequence correspond to different luminous intensities of the light source modules.

57. The method according to any one of claims 40 to 56, wherein: The aperture of the light-emitting surface of the light source module is the same as the aperture of the lens module or the difference between them is less than 1 / 5 of the aperture of the light-emitting surface. Alternatively, the aperture of the light-emitting surface of the light source module is greater than twice the light-transmitting aperture of the lens module.

58. The method according to any one of claims 40 to 56, wherein: The detection angle range of the photosensitive array covers the total reflection angle range of the lens module.

59. The method according to any one of claims 40 to 56, wherein: The half-maximum width of the output light of the light source module is less than 5 nm, or a narrow-band filter is provided on the output light path of the light source module, and the half-maximum width of the output light after filtering by the narrow-band filter is less than 5 nm.

60. The method according to any one of claims 40 to 56, characterized in that A light homogenizer is provided on the outgoing light path of the light source module.

61. The method according to any one of claims 40 to 56, wherein: The light emitted by the light source module is in the green light band, and the photosensitive array is a CMOS sensor with a Bell pattern of RGGB.

62. The method according to any one of claims 40 to 56, wherein: Before determining the brightness mutation boundary in the detection image according to the detection image, the method further includes: It is determined that an absolute value of a difference between the brightness of the detected image and a preset brightness is greater than a threshold.

63. The method according to any one of claims 40 to 56, wherein: Before determining the brightness mutation boundary in the detection image according to the detection image, the method further includes: Noise filtering is performed on the target pixel row according to at least some of the pixel rows above and below the target pixel row in the detection image.

64. The method according to any one of claims 40 to 56, wherein: The performing noise filtering on the target pixel row according to at least some pixel rows above and below the target pixel row in the detection image comprises: A weighted average of the pixel value of the target pixel row and the pixel values ​​of at least part of the pixel rows is used as the pixel value of the target pixel row after noise filtering.

65. The method according to any one of claims 40 to 56, wherein: Before determining the brightness mutation boundary in the detection image according to the detection image, the method further includes: determining pixel rows in the detection image that are affected by stray light, The pixel row affected by the stray light is not used to determine the refractive index of the medium located on the side of the total reflection interface facing away from the light source module.

66. The method according to any one of claims 40 to 56, wherein: The detection image is obtained by weighted summing of multiple frames of images acquired by the photosensitive array.

67. The method according to any one of claims 40 to 56, wherein: The method further comprises: Acquiring the temperature of the medium outside the total reflection interface and the temperature of the total reflection interface; The refractive index of the medium is calculated based on the pre-stored relationship model between the temperature of the medium to be measured, the temperature of the total reflection interface and the refractive index of the medium to be measured, and the acquired temperature of the medium outside the total reflection interface and the temperature of the total reflection interface.

68. The method according to any one of claims 40 to 56, wherein: Also includes: The turbidity of the medium located outside the reflection module is calculated according to the detection image.

69. The method according to claim 68, characterized in that The detection image includes a non-reflective area; Calculating the turbidity of the medium located outside the reflection module according to the detection image includes: Obtaining the scattered brightness of the non-total reflection area in the non-reflection area and / or the blurring degree of the brightness mutation boundary; wherein the non-total reflection area in the non-reflection area corresponds to an area in the non-reflection area that is incident on the reflective module at an angle less than the total reflection angle and then incident on the photosensitive array; The turbidity is calculated according to the scattered brightness of the non-total reflection area in the non-reflection area and / or the blurring degree of the brightness mutation boundary.

70. The method according to claim 69, wherein The non-reflective area further includes a total reflection area located on one side of the non-total reflection area; The obtaining of the scattered brightness of the non-total reflection area in the non-reflection area includes: The scattered brightness of the non-total reflection area of ​​the non-reflection area in the detection image is calculated using the brightness of the total reflection area in the non-reflection area as a reference value.

71. The method according to claim 69, wherein The calculating of the turbidity according to the scattered brightness of the non-total reflection area in the non-reflection area and / or the blurring degree of the brightness mutation boundary includes: When the concentration of the liquid to be tested is lower than a preset concentration, calculating the turbidity of the liquid to be tested based on the scattered brightness of the non-total reflection area on the non-reflection area in the detection image; When the concentration of the liquid to be tested is higher than a preset concentration, the turbidity of the liquid to be tested is calculated according to the blurring degree of the brightness mutation boundary on the detection image.

72. The method according to claim 69, wherein The medium located outside the reflection module is a liquid to be measured; the method further includes: Obtaining the volume of the liquid to be tested; The calories of the liquid to be tested are calculated according to the refractive index, turbidity and volume of the liquid to be tested.

73. The method according to claim 69, characterized in that The medium located outside the reflection module is a liquid to be measured; the method further includes: Acquiring auxiliary information using an auxiliary device, wherein the auxiliary device includes a colorimeter and the auxiliary information includes the color of the liquid to be tested; or, the auxiliary device includes an impedance meter and the auxiliary information includes the ion content of the liquid to be tested; or, the auxiliary device includes a pH meter and the auxiliary information includes the acidity value of the liquid to be tested; The type of the liquid to be tested is determined according to the auxiliary information and the refractive index and / or turbidity of the liquid to be tested.

74. The method according to any one of claims 40 to 56, wherein: Before emitting a light beam to the reflection module in the refractometer, the method further includes: The liquid is emitted to clean the target object, and the medium located outside the reflective module is the liquid after cleaning the target object; The method further comprises: The cleanliness of the target object is determined based on the refractive index of the liquid after cleaning the target object.

75. The method according to claim 74, characterized in that The method further comprises: Whether the target object needs to be further cleaned is determined according to the cleanliness of the target object.

76. The method according to any one of claims 40 to 56, wherein: Before emitting the light beam to the reflection module in the refractometer, the method further includes: Fixing the refractometer inside the inner wall of the pipeline or on the surface of the inner wall of the pipeline; Wherein, the refractometer is used to measure the refractive index of the flowing liquid in the pipeline, and the brightness mutation boundary includes a brightness mutation boundary corresponding to the flowing liquid in the pipeline.

77. A detection device, characterized in that: A refractometer comprising the steps of any one of claims 1 to 39.

78. The detection device according to claim 77, characterized in that The detection device is a smart cup, comprising a cup cover and a cup body; The refractometer is arranged at the cup lid or the bottom of the cup body, and is used to detect the refractive index of the liquid in the cup body; a thin film is arranged on the bottom of the cup body, and a closed space is formed between the thin film and the bottom of the cup body; a micro-air pressure sensor is provided in the closed space, and is used to detect the volume of the liquid in the cup body; a calculation module is also provided in the closed space, and is used to calculate the calories of the liquid based on the volume and refractive index of the liquid.

79. The detection device according to claim 77, characterized in that The detection device is an intelligent scale, including a scale body; the refractometer is arranged in the scale body, and the surface of the scale body is also provided with a liquid accommodating area and a first display area, the refractometer is used to detect the refractive index of the liquid in the liquid accommodating area, and the first display area is used to display the refractive index of the liquid; the scale body is also provided with a weighing area and a second display area, and the second display area is used to display the weight of the object on the weighing area.

Images