A method and apparatus for measuring ultraviolet spectrum

Abstract

The present application relates to the field of spectral measurement, in particular to a kind of ultraviolet spectrum measurement method, comprising: fluorescence gradual conversion device is converted into visible light by the ultraviolet light to be measured obtained, and is transmitted to image sensing device;Image sensing device converts the visible light into visible light intensity image, and is transmitted to data processing device;According to the visible light intensity image obtained by data processing device, and according to the preset reconstruction algorithm, the spectrum of the ultraviolet light to be measured is calculated.The present application does not need to use the slit, grating and complex collimating focusing light path of existing spectrometer, the present application uses black and white surface array CCD to receive incident light in large area, and converts the ultraviolet light insensitive to CCD into sensitive visible light, greatly improves the intensity and utilization of optical signal, greatly reduces cost, reduces volume, and can very conveniently improve resolution and conversion measurement range.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of spectral measurement, in particular to a method for measuring ultraviolet spectrum and an ultraviolet spectrum measuring device. BACKGROUND

[0002] Spectrometer is an important device for measuring spectral characteristics of light source and substance, and is the most basic analysis instrument in spectroscopy and spectral technology. It is widely used in environmental monitoring, lamp testing, LED brightness color temperature color rendering index, industrial control, chemical analysis, food quality detection, material analysis, clinical examination, aerospace remote sensing and scientific education fields. Spectrum is an image in which various monochromatic light components in complex light are arranged in order according to wavelength or the intensity distribution of each monochromatic light according to wavelength. Spectrometer is an instrument for decomposing complex light into spectral lines and measuring the spectrum.

[0003] A typical spectrometer is composed of the following basic parts:

[0004] 1. Entrance slit: forms the object point of the imaging system of the spectrometer under the irradiation of incident light, and is usually only 20-200 microns wide;

[0005] 2. Collimating element: makes the light emitted by the slit into parallel light. The collimating element can be a separate lens, mirror or directly integrated on the dispersive element;

[0006] 3. Dispersive element: usually uses a grating or a prism to disperse the light signal in space according to wavelength, and now mainly uses a grating;

[0007] 4. Focusing element: focuses the dispersed light beam to form a series of images of the entrance slit on the focal plane, where each image point corresponds to a specific wavelength;

[0008] 5. Detector array: placed on the focal plane, used to measure the intensity of each wavelength image point, usually using a linear array CCD.

[0009] From the basic composition of the existing spectrometer and the definition of the spectrometer, it can be seen that the core is to decompose complex light into monochromatic light dispersed in space according to wavelength, so there are the following main problems in the existing spectrometer:

[0010] 1. Weak light signal, the entrance slit only allows very narrow light beam to enter the spectrometer, the purpose is to minimize the overlap of different wavelengths of light in space after beam splitting to reduce the resolution;

[0011] 2. Expensive grating, in order to improve the spectral resolution, the grating needs to be very precise, with hundreds or even thousands of etched lines per millimeter;

[0012] 3. Complex collimating and condensing optical path;

[0013] 4. The light intensity on a linear CCD is extremely weak. After the light is split by the grating, only a portion of the light intensity is usable. Such a weak light signal is further broadened onto a linear CCD that is only a few centimeters wide after being split, and the light intensity becomes even weaker.

[0014] 5. CCDs are mainly sensitive to visible light and near-infrared light, but have very low sensitivity to ultraviolet light. The sensitivity drops sharply as the wavelength gets shorter. Usually, expensive, thinned back-illuminated linear CCDs with special modifications are needed to measure ultraviolet spectra, and even cooling devices are needed to reduce noise.

[0015] 6. Not replaceable. Spectrometers are usually equipped with different gratings depending on the measurement range, such as the visible light range, infrared range, and ultraviolet range. The grating position, detector position, and optical path are also fixed according to this design. If you want to change the measurement range, you not only have to replace the grating, but also change the optical path and detection element, which is practically not feasible. Summary of the Invention

[0016] In view of the above problems, embodiments of the present invention are proposed to provide a method and apparatus for measuring ultraviolet spectra that overcome or at least partially solve the above problems.

[0017] To address the aforementioned issues, this invention discloses a method for measuring ultraviolet spectra, comprising: a fluorescence gradient conversion device converting the acquired ultraviolet light to be measured into visible light and transmitting it to an image sensing device;

[0018] The image sensing device converts the visible light into a visible light intensity image and transmits it to the data processing device;

[0019] The spectrum of the ultraviolet light to be measured is calculated based on the visible light intensity image obtained by the data processing device and the preset reconstruction algorithm.

[0020] Preferably, the fluorescence gradient conversion device converts the acquired ultraviolet light to be measured into visible light and transmits it to the image sensing device, comprising:

[0021] Obtain the excitation spectrum curve of the fluorescence gradient conversion device.

[0022] Preferably, obtaining the excitation spectrum curve of the fluorescence gradient conversion device includes:

[0023] The fluorescence gradient conversion device is irradiated sequentially and uniformly with single-wavelength ultraviolet light of different wavelengths from a standard ultraviolet light source using a monochromator.

[0024] The data processing device generates a visible light intensity image of the single wavelength, divides the visible light intensity image into N transmission units, and calculates the luminous intensity of the transmission units.

[0025] generate a luminescence intensity versus ultraviolet wavelength curve according to the variation of the luminescence intensity in the transmission unit;

[0026] compare the luminescence intensity versus wavelength curve of the N transmission units with the emission spectrum of the standard ultraviolet light source to obtain an excitation spectrum curve.

[0027] Preferably, the comparison of the luminescence intensity versus wavelength curve of the N transmission units with the emission spectrum of the standard ultraviolet light source to obtain an excitation spectrum curve comprises:

[0028] obtain the excitation rate a of the more dense wavelength positions by interpolation method n .

[0029] Preferably, the image sensing device converts the visible light into a visible light intensity image and transmits to the data processing device comprises:

[0030] obtain the visible light transmitted by the fluorescent gradual transition conversion sheet preset to be continuously linearly changed or nonlinearly changed or stepwisely changed;

[0031] obtain the visible light intensity image converted by the image sensing device composed of black and white area array CCD or black and white area array CMOS;

[0032] The visible light intensity image is transmitted to the data processing device.

[0033] Preferably, the visible light intensity image obtained by the data processing device and the calculation of the spectrum of the to-be-tested ultraviolet light according to the preset reconstruction algorithm comprises:

[0034] divide the visible light intensity image into N luminescence units;

[0035] the visible light intensity image obtained by the data processing device and the division of the fluorescent gradual transition conversion device into N excitation units according to the N luminescence units;

[0036] calculate the luminescence intensity P of the luminescence unit;

[0037] select N uniformly spaced wavelength positions in the luminescence unit, and establish an equation containing the incident ultraviolet light intensity x n corresponding to the wavelength position according to the luminescence intensity P and the excitation rate a n ;

[0038] establish N equations containing the incident ultraviolet light intensity x n and the luminescence intensity P m , and calculate the spectrum of the to-be-tested ultraviolet light.

[0039] Preferably, the wavelength positions of N evenly spaced wavelengths in the excitation unit are selected, and the luminescence intensity P and the excitation rate α corresponding to the wavelength positions are determined according to the luminescence intensity P and the excitation rate α corresponding to the wavelength positions n The equation including the incident ultraviolet light intensity x corresponding to the wavelength positions is established n , including:

[0040] The equation P = x1α1+x2α2+…+x n α n +…+x N α N .

[0041] Preferably, the luminescence intensity P of N equations including the incident ultraviolet light intensity x is established, and the spectrum of the to-be-measured ultraviolet light is calculated n m , including:

[0042] The matrix equation group P = x1α+x2α+…+x m α m-1 +x2α m-2 +…+x n α m-n +…+x N α m-N .

[0043] The embodiment of the present application also discloses a measurement device of ultraviolet spectrum, comprising: an imaging assembly, a fluorescent gradual conversion device, an image sensing device, and a data processing device.

[0044] The fluorescent gradual conversion device comprises a fluorescent gradual conversion sheet, which is closely attached to the image sensing device.

[0045] The image sensing device is electrically connected to the data processing device.

[0046] Preferably, the fluorescent gradual conversion device comprises a fluorescent gradual conversion sheet for receiving incident to-be-measured ultraviolet light and converting it into visible light.

[0047] The light-transmitting surface of the fluorescent gradual conversion device is closely attached to the data processing device.

[0048] The data processing device comprises an image sensing device for converting the visible light into a visible light intensity image.

[0049] The image sensing device is electrically connected to the data processing device.

[0050] The data processing device is used for measuring the visible light intensity and calculating the spectrum of the to-be-measured ultraviolet light by using a reconstruction algorithm.

[0051] Preferably, the fluorescent gradual conversion sheet comprises:​

[0052] The fluorescent gradual change conversion sheet is arranged at the output position of the imaging assembly.

[0053] The fluorescent gradual change conversion sheet is composed of multiple fluorescent gradual change layers, specifically, at least three fluorescent gradual change layers, fluorescent gradual change layer A, fluorescent gradual change layer B and fluorescent gradual change layer C, and the ultraviolet excitation spectrum of each fluorescent gradual layer is different.

[0054] Preferably, the fluorescent gradual change conversion sheet further comprises:

[0055] a light receiving surface for receiving ultraviolet light to be tested and a light transmitting surface for transmitting visible light;

[0056] The light transmitting surface is closely attached to the image sensing device.

[0057] The density or thickness of each fluorescent gradual change layer gradually changes in multiple directions, and the directions of the gradual changes between the fluorescent gradual change layers are different.

[0058] Preferably, the imaging assembly comprises a lens group and a monochromator.

[0059] The input port of the monochromator is arranged at the position irradiated by the standard ultraviolet light lamp.

[0060] The output port of the monochromator is arranged at the input position of the lens group and is located at the appropriate focusing position of the lens group.

[0061] The lens group comprises at least one concave lens and at least one convex lens, and is arranged at the front end of the fluorescent gradual change conversion sheet.

[0062] Preferably, the fluorescent gradual change layer comprises:

[0063] The fluorescent gradual change layer is a material that emits ultraviolet excitation fluorescence.

[0064] The fluorescent gradual change layer A is linearly and continuously gradually changed, the fluorescent gradual change layer B is gradually changed in steps, the directions of the gradual changes of the fluorescent gradual change layer A and the fluorescent gradual change layer B are perpendicular to each other, and the density or thickness of the fluorescent gradual change layer C is distributed in regions.

[0065] The fluorescent gradual change layer A, the fluorescent gradual change layer B and the fluorescent gradual change layer C are sequentially printed on a substrate layer.

[0066] Preferably, the image sensing device comprises a black and white area array CCD or a black and white area array CMOS.

[0067] The black and white area array CCD or the black and white area array CMOS is electrically connected to a data processing device, and the diagonal length of the target surface of the photosensitive surface ranges from 3mm to 64mm.

[0068] Preferably, the data processing device comprises:

[0069] The visible light intensity image is divided into a predetermined number of light-emitting units in rectangular regions of the same size and shape.

[0070] The data processing device calculates the to-be-measured ultraviolet light spectrum according to a preset reconstruction algorithm.

[0071] Preferably, the fluorescent gradual conversion sheet further comprises:

[0072] The fluorescent gradual conversion sheet comprises a plurality of excitation units divided into a number equal to that of the light-emitting units, and each of the excitation units is a rectangular region of the same size and shape.

[0073] Each of the excitation units is an excitation unit having a distinguishable excitation curve that is significantly different from an error.

[0074] The excitation units correspond one-to-one to the light-emitting units and are equal in number.

[0075] Preferably, the data processing device further comprises a computer and a data processing software installed in the computer for obtaining the to-be-measured ultraviolet light spectrum using a reconstruction algorithm.

[0076] The present application has the following advantages:

[0077] The core of the present application is to solve the problems of weak signal, low light utilization, low resolution, high cost, and large size of the currently widely used spectrometer with a slit for light input and a grating for light splitting, especially the low response coefficient of the CCD to ultraviolet light. A new method and device for measuring ultraviolet spectrum are proposed, which uses a fluorescent gradual conversion sheet combined with a black-and-white area array CCD and a new algorithm. Without a slit and a grating, the fluorescent gradual conversion sheet converts ultraviolet light into visible light that is highly responsive to the black-and-white area array CCD. The visible light intensity of each excitation unit of the fluorescent gradual conversion sheet is measured, and the excitation curve of the excitation unit is combined to calculate the distribution of the to-be-measured ultraviolet light intensity with wavelength, i.e., the spectrum, by a reconstruction algorithm. Not only is the slit, grating, and complex collimating and focusing light path of the existing spectrometer eliminated, but also the area array CCD is used to receive incident light, the to-be-measured ultraviolet light is converted into visible light, the intensity and utilization of the light signal are greatly improved, the cost is greatly reduced, the size is reduced, the resolution and the measurement range can be easily improved, and therefore high-quality spectral data can be obtained at a low cost. BRIEF DESCRIPTION OF DRAWINGS

[0078] Figure 1 is a step flow chart of an embodiment of a method for measuring ultraviolet spectrum of the present application;

[0079] Figure 2 is a schematic diagram of the three-dimensional structure of a fluorescent gradual conversion sheet of a UV spectrum measuring device of the present application;

[0080] Figure 3 is a schematic diagram of the structure of an embodiment of a UV spectrum measuring device of the present application;

[0081] Figure 4 is a schematic diagram of the structure of another embodiment of a UV spectrum measuring device of the present application.

[0082] 1 UV light to be measured, 2 fluorescent gradual conversion sheet, 3 image sensing device, 4 computer, 5 standard UV light source, 6 monochromator, 7 lens group, 21 base material, 22 fluorescent ink layer A, 23 fluorescent ink layer B, 24 fluorescent ink layer C, 41 visible light intensity image, 411 light-emitting unit. DETAILED DESCRIPTION

[0083] In order to make the above-mentioned objects, features and advantages of the present application more apparent and comprehensible, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0084] One of the core ideas of the embodiments of the present application is that N excitation units and N light-emitting units are respectively divided on the fluorescent gradual conversion sheet and the visible light intensity image obtained after conversion by the fluorescent gradual conversion sheet, N evenly spaced wavelength positions are selected on the light-emitting units, and then the excitation spectrum curve of the excitation units and the light-emitting intensity of the light-emitting units are measured, so as to construct N equations containing wavelength positions incident UV light intensity x n , and the UV light spectrum to be measured, i.e., the distribution of the intensity of the UV light to be measured with the wavelength, can be obtained by solving the equations. Specifically, the fluorescent gradual conversion sheet is in close contact with the surface array CCD or CMOS photosensitive surface, and has the same size and shape. The UV light to be measured is uniformly irradiated onto the fluorescent gradual conversion sheet, and the black and white surface array CCD or CMOS obtains a visible light intensity image. The data processing device divides N light-emitting units of the same size from the visible light intensity image, and calculates the light-emitting intensity P of the light-emitting units. Assuming that the relative intensity of the UV light to be measured on N evenly spaced wavelengths is x n (n = 1, 2, …, N), the excitation rate a n (n = 1, 2, …, N) about N wavelengths is obtained according to the light-emitting intensity P and the average excitation spectrum curve at the position of the fluorescent gradual conversion sheet corresponding to the light-emitting units, and then the equation containing the incident UV light intensity x n and the excitation rate a n is established, i.e., P = x1a1+x2a2+…+x N a N N different excitation units on the fluorescent gradual conversion sheet can establish N equations containing the incident UV light intensity xn The equation is used to calculate the to-be-measured ultraviolet spectrum. The present application does not need a slit and a grating, uses a surface array CCD instead of a traditional linear array CCD, converts the ultraviolet light which is not sensitive to the CCD into visible light which is sensitive, improves the sensitivity and resolution by several orders of magnitude, greatly reduces the volume, and reduces the cost.

[0085] The standard ultraviolet light source used in the embodiment of the present application is a standard ultraviolet lamp, and the wavelength covers the known ultraviolet wavelength range.

[0086] Referring to Figure 1 , a step flow chart of an embodiment of the present application is shown, which can specifically include the following steps:

[0087] S100, obtaining to-be-measured ultraviolet light and converting the to-be-measured ultraviolet light into visible light;

[0088] S200, obtaining the converted visible light and converting the obtained visible light into a visible light intensity image;

[0089] S300, obtaining the visible light intensity image and calculating the corresponding light intensity distribution with respect to the wavelength by using a reconstruction algorithm;

[0090] S400, obtaining the spectrum of the to-be-measured ultraviolet light according to the calculation result.

[0091] The fluorescence gradual conversion device converts the obtained to-be-measured ultraviolet light into visible light and transmits the visible light to the image sensing device; the image sensing device converts the visible light into a visible light intensity image and transmits the visible light intensity image to the data processing device; the data processing device obtains the visible light intensity image and calculates the spectrum of the to-be-measured ultraviolet light according to a preset reconstruction algorithm.

[0092] The spectrum of the to-be-measured ultraviolet light is calculated, specifically: the image sensing device obtains the visible light emitted by the fluorescence gradual conversion device and converts the visible light into a visible light intensity image; the data processing device divides the obtained visible light intensity image into N identical rectangular regions, i.e., light emitting units, according to the visible light intensity image; the light emitting units correspond to the excitation units on the fluorescence gradual conversion sheet. After the N light emitting units are divided, the data processing device calculates and records the light emitting intensity P of each light emitting unit.

[0093] N wavelength positions with uniform intervals are selected in the light emitting unit, and the excitation rate alpha n The equation of the incident ultraviolet light intensity x n corresponding to the wavelength position is established,

[0094] P = x1a1+ x2a2+ … + x n a n + … + x N a N .

[0095] More or less units can be divided according to the need, but the number of wavelength positions must not be more than the number of the first light-emitting units or the first excitation units, otherwise the matrix equation has no solution and the spectrum of the ultraviolet light to be measured cannot be calculated.

[0096] N equations of the light intensity P containing the incident ultraviolet light intensity x n are established, and the spectrum of the ultraviolet light to be measured, i.e. the distribution of the light intensity of the ultraviolet light to be measured with the wavelength, can be obtained by solving the equation group composed of the N equations of the light intensity P containing the incident ultraviolet light intensity x n . The number of the light-emitting units or the excitation units is equal to the number of the wavelength positions.

[0097] In another embodiment, the embodiment discloses a method for measuring the spectrum of ultraviolet light, which comprises a new method for measuring the spectrum of ultraviolet light by using a fluorescent gradual conversion sheet 2 combined with an image sensing device 3. The image sensing device 3 can be a black-and-white area array CCD or a black-and-white area array CMOS, which is suitable for all models and can be selected according to the need for testing. The sensitivity, resolution and cost can be selected to select a suitable black-and-white area array CCD or a black-and-white area array CMOS. The method does not need an incident slit or a grating to decompose the light according to the wavelength and expand in space, and does not need a specially improved expensive thinned back-illuminated linear array CCD. The method uses a fluorescent gradual conversion sheet 2, a black-and-white area array CCD, a computer 4 and a set of data processing software installed in the computer 4. The fluorescent gradual conversion sheet 2 is made of a quartz sheet or an organic transparent sheet or a film printed with three or more fluorescent inks. The size of the fluorescent gradual conversion sheet 2 is the same as the light-sensing area of the black-and-white area array CCD, and the fluorescent gradual conversion sheet 2 is tightly attached to the light-sensing surface of the CCD.

[0098] The three or more fluorescent materials used are organic fluorescent materials or inorganic fluorescent materials that can efficiently emit visible light under ultraviolet excitation. The excitation curves of the three or more fluorescent materials are wideband and different from each other but partially overlap, which can effectively cover the entire ultraviolet spectrum range (usually 200 nm to 400 nm).

[0099] Three or more fluorescent inks respectively present a gradient from deep to shallow along the surface of the fluorescent gradient conversion sheet 2 in different directions, and the superimposed effect makes the relative proportion of the three or more fluorescent inks at any point on the fluorescent gradient conversion sheet 2 not the same. When the ultraviolet light irradiates the surface of the fluorescent gradient conversion sheet 2, the visible light emitted can be measured on the back, and for each point, the curve of the light intensity with the wavelength of the ultraviolet light, that is, the excitation curve, is different and can be accurately measured. When the to-be-measured ultraviolet light 1 irradiates the fluorescent gradient conversion sheet 2, the to-be-measured ultraviolet light 1 is converted into visible light, the black-and-white area CCD obtains the visible light intensity image 41 of the entire fluorescent gradient conversion sheet 2, and transmits to the data processing software. The data processing software uniformly divides the visible light intensity image 41 into a plurality of same rectangular regions (referred to as: light emitting units), and the region on the fluorescent gradient conversion sheet 2 corresponding to the light emitting unit is referred to as an excitation unit. The data processing software calculates the light intensity of each light emitting unit, and then combines the excitation curve of the excitation unit corresponding to each light emitting unit, that is, the excitation rate at each wavelength position, to list a matrix equation, and calculate the light intensity distribution of the to-be-measured ultraviolet light 1 with the wavelength through a reconstruction algorithm, to obtain the spectrum thereof.

[0100] The number of light emitting units is the same as the number of wavelength points of the to-be-measured ultraviolet light 1, and if the light intensity of the to-be-measured ultraviolet light 1 at N wavelength positions is to be calculated, the visible light intensity image 41 needs to be divided into N light emitting units, and the excitation curves of the N excitation units corresponding thereto need to be measured in advance.

[0101] The ultraviolet spectrum measurement method described in the application is a completely new method, specifically: the to-be-measured ultraviolet light 1 uniformly irradiates each excitation unit of the fluorescent gradient conversion sheet 2, assuming that the light intensity of the to-be-measured ultraviolet light 1 at N uniformly spaced wavelength positions on the excitation unit is x n (n is a positive integer from 1 to N), and the excitation rate of the known excitation curve thereof at the N wavelength positions is α n (n is a positive integer from 1 to N), then the light intensity P on the light emitting unit is equal to the light intensity x n at each wavelength position of the to-be-measured ultraviolet light 1, multiplied by the excitation rate α n at the wavelength position, and then added,

[0102] that is: P=x1α1+x2α2+…+x n α n +…+x N α N ;

[0103] In this way, each light emitting unit obtains an equation containing N unknowns x nThe equation of (n is a positive integer from 1 to N) is obtained, N light emitting units are obtained N equations, and the light intensity of the to-be-measured ultraviolet light 1 at N wavelength positions, i.e. the distribution of the light intensity with the wavelength, can be obtained by solving the N-order equation group (or matrix equation) of the N equations, so that the spectrum of the to-be-measured ultraviolet light 1 is obtained.

[0104] More or fewer light emitting units 411 can also be divided according to the need for the visible light intensity image 41 area, but the number of selected wavelength positions must not be more than the number of excitation units or light emitting units 411, otherwise the matrix equation has no solution, and the spectrum of the to-be-measured ultraviolet light 1 cannot be calculated.

[0105] It should be noted that, for the method embodiments, in order to simply describe, they are all expressed as a series of action combinations, but those skilled in the art should know that the embodiments of the present application are not limited by the action sequence described, because according to the embodiments of the present application, certain steps can be performed in other order or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification all belong to preferred embodiments, and the actions involved are not necessarily necessary for the embodiments of the present application.

[0106] Compared with the existing method of measuring spectrum by using a slit and a grating, the method and device for measuring spectrum by using the fluorescent gradual change conversion sheet 2 combined with the black and white area array CCD are completely different new method and new device, and have the following advantages:

[0107] 1. No slit is needed for light entering, no grating is needed, no collimation and focusing light path is needed, and the area array CCD directly receives the visible light of the fluorescent gradual change conversion sheet 2;

[0108] 2. The area array CCD image sensor usually has several hundred thousand to several million pixels, which is much more than the several hundred to several thousand pixels of the linear CCD detector in the existing spectrometer, and the photosensitive area is also several orders of magnitude larger, so the light signal intensity is also several orders of magnitude higher;

[0109] 3. The low response efficiency of the CCD to the ultraviolet light is converted into high response efficiency of the visible light, which greatly enhances the signal strength;

[0110] 4. The cost is greatly reduced, and the size of the entire device is also greatly reduced;

[0111] 5. The resolution is adjustable, and the resolution of the spectrum depends on the interval of the adjacent wavelength. In the new method of the present application, the number of wavelength measurement points is equal to the number of divided light emitting units, and the resolution of the spectrum wavelength can be improved by dividing more densely.

[0112] In another embodiment, the spectrum of an unknown ultraviolet light source is measured, which has a spectral range between 200 nm and 400 nm. The image sensing device 3 used in this embodiment is a 1 / 2.7 inch black and white area array CCD with 300,000 pixels, and the photosensitive surface size is 5.27 mm x 3.96 mm. The reason for using a black and white area array CCD instead of a color CCD is that only the light intensity is measured, and the color is not considered.

[0113] The size of the fluorescent gradient conversion sheet 2 is the same as the photosensitive surface size of the black and white area array CCD, wherein the fluorescent gradient conversion sheet 2 is composed of a transparent organic film as a base material 21, and fluorescent ink layers A 22, B 23, and C 24 printed thereon. The depth of each ink printing layer can be adjusted from 0 to 100%. The fluorescent gradient conversion sheet 2 is divided into eight smaller rectangular areas (sub-zones). The first fluorescent material of the fluorescent ink layer A 22 and the second fluorescent material of the fluorescent ink layer B 23 have a linear change range and direction from thick to thin, with the thickest being 100% and the thinnest being 0%. In the eight sub-zones, the first fluorescent material and the second fluorescent material change in the same way. In addition, the third fluorescent material of the fluorescent ink layer C 24 is uniformly printed in the eight sub-zones, but the depth is different, and the depths are 0%, 14.3%, 28.6%, 42.9%, 57.1%, 71.4%, 85.7%, and 100%, respectively. The depth of the three fluorescent inks is determined by the ink dot density or thickness.

[0114] In order to more clearly describe the structure of the fluorescent gradient conversion sheet 2, Figure 2 The three ink depth gradient directions and their mutual superposition relationship can be clearly seen from the perspective of the fluorescent gradient conversion sheet 2. The excitation curves of the three fluorescent inks are different in shape and peak position, and the three excitation curves together cover the entire ultraviolet light band (200-400 nm). The first fluorescent material of the fluorescent ink layer A 22 is YAG: Ce, the second fluorescent material of the fluorescent ink layer B 23 is Ca9Mg1.5(PO4)7: Eu, and the third fluorescent material of the fluorescent ink layer C 24 is Ba3Si6O12N2: Eu, all of which can efficiently emit yellow visible light under ultraviolet excitation.

[0115] The black-and-white area array CCD converts the yellow visible light into a visible light intensity image 41 and transmits to the data processing software. The data processing software uniformly divides the visible light intensity image 41 into a plurality of same rectangular areas, and the area on the fluorescent gradual conversion sheet 2 corresponding to the light emitting unit 411 is referred to as an excitation unit. The data processing software calculates the light intensity of each light emitting unit 411, and then combines the excitation curve of the excitation unit corresponding to each light emitting unit 411, i.e. the excitation rate at each wavelength position, to list a matrix equation, and calculate the distribution of the light intensity of the to-be-measured ultraviolet light 1 with wavelength through a reconstruction algorithm, to obtain the spectrum thereof.

[0116] Another embodiment and in combination Figure 3 As shown in the figure, the embodiment discloses a measurement method of ultraviolet spectrum, which is used for spectrum measurement of unknown ultraviolet light source, and specifically as follows:

[0117] The excitation curve data of all 512 excitation units of the fluorescent gradual conversion sheet 2 can be used to calculate the spectrum of the to-be-measured ultraviolet light 1 through the measurement of the visible light intensity of the fluorescent gradual conversion sheet 2 and the reconstruction algorithm. Specifically, the to-be-measured ultraviolet light 1 irradiates on the fluorescent gradual conversion sheet 2, the black-and-white area array CCD closely attached to the fluorescent gradual conversion sheet 2 shoots the visible light intensity image, the data processing software calculates and records the light intensity of the visible light intensity image of the 512 light emitting units 411, and the data processing software can calculate the distribution of the light intensity of the to-be-measured ultraviolet light 1 with wavelength, i.e. the spectrum, through the reconstruction algorithm according to the light intensity data of the 512 light emitting units 411 and the excitation curve of the corresponding 512 excitation units;

[0118] The following is the calculation process of the reconstruction algorithm:

[0119] For convenience of description, each light emitting unit 411 is numbered: from the first unit in the upper left corner to the 512th unit in the lower right corner, they are #1, #2, #3, …, #512, and 512 wavelength positions are uniformly selected in the ultraviolet wavelength interval of 200 nm to 400 nm, i.e. wavelength positions, numbered: λ1, λ2, λ3, …, λ512. 512 .

[0120] Because the excitation curve of each excitation unit is known and accurately measured, the excitation rates of each excitation unit at the 512 wavelength positions are also known. It is assumed that the excitation rate of the excitation unit corresponding to the #1 light emitting unit 411 at the wavelength position λ1 is α1, the excitation rate at the wavelength position λ2 is α2, …, and the excitation rate at the wavelength position λ512 is α512. 1-1 Similarly, the excitation rate of the excitation unit corresponding to the #m light emitting unit 411 at the wavelength position λm is αm. 1-2 Similarly, the excitation rate of the excitation unit corresponding to the #m light emitting unit 411 at the wavelength position λm is αm. 512 Similarly, the excitation rate of the excitation unit corresponding to the #m light emitting unit 411 at the wavelength position λm is αm. 1-512 Similarly, the excitation rate of the excitation unit corresponding to the #m light emitting unit 411 at the wavelength position λm is αm. m Similarly, the excitation rate of the excitation unit corresponding to the #m light emitting unit 411 at the wavelength position λm is αm. n-m(1≤n≤512, 1≤m≤512), these are all known quantities;

[0121] Since the ultraviolet light 1 to be tested is uniformly irradiated onto the surface of the fluorescent gradient conversion sheet 2, and the 512 emitting units 411 and their corresponding 512 excitation units are of the same size and shape, the light intensity of the ultraviolet light 1 irradiating each excitation unit is also the same. The light intensity of the ultraviolet light 1 at wavelength λ1 is set as x1, the light intensity at wavelength λ2 is x2, ..., and so on, at the incident surface of each excitation unit. m The light intensity at wavelength x m , ..., in λ 512 The light intensity at wavelength x 512 These are all unknowns. Once these unknowns are calculated, the spectrum of the ultraviolet light to be measured, 1, can be obtained.

[0122] Since the excitation curve of each excitation unit is different, the light intensity and composition of each light-emitting unit 411 are also different. For any wavelength, its light intensity is equal to its incident ultraviolet light intensity multiplied by its excitation rate in that excitation unit.

[0123] That is: x × α.

[0124] Let the visible light intensity values ​​of each light-emitting unit 411 measured by the black-and-white area CCD be P1, P2, ..., P... m ... P 512 These are all known quantities measured by the black-and-white area CCD array. So, for any single emitting unit 411, such as #m emitting unit, what is the visible light intensity P? m It is the sum of the light intensities of all 512 wavelengths (wavelength positions) of visible light.

[0125] That is: P m =x1α m-1 +x2α m-2 +…+x n α m-n +…+x 512 α m-512 ,

[0126] This is a string containing x1, x2, ..., x... 512 A system of 512 linear equations with a total of 512 unknowns is obtained from 512 light-emitting units 411. These 512 equations are distinct and have no linear relationship.

[0127]

[0128] In matrix equation form, it is:

[0129] αx = P or: x = α-1 P;

[0130] wherein a is a 512x512 square matrix of coefficients of the excitation rate of 512 excitation units at 512 wavelength positions, a -1 is its inverse matrix, x is a column vector of 512 unknowns, and P is a constant column vector composed of the measured visible light intensity data of 512 light emitting units 411.

[0131] Solving this equation group composed of 512 512-element linear equations (or matrix equation), a solution about unknowns x1, x2, …, x 512 is obtained, that is, the distribution of the light intensity of the to-be-measured ultraviolet light 1 with wavelength, that is, the spectrum.

[0132] Another embodiment is shown in combination with the accompanying drawings Figure 4 , and the embodiment discloses a measurement method of ultraviolet spectrum, and specifically as follows:

[0133] The fluorescent gradual conversion sheet 2 is closely attached to the CCD photosurface, and the surface of the organic glass printed with fluorescent ink faces the incident light. The to-be-measured ultraviolet light 1 is the standard ultraviolet light emitted by the standard ultraviolet light source 5, and the device further comprises a monochromator 6 and a set of beam expander lens groups 7. The standard ultraviolet light refers to the ultraviolet light emitted by a standard lamp with a known emission spectrum and covering the entire ultraviolet light range. The monochromator 6 is an instrument that can sequentially output single-wavelength ultraviolet light according to the wavelength of the standard ultraviolet light. The beam expander lens group 7 expands the narrow single-wavelength ultraviolet light beam into a parallel single-wavelength ultraviolet light of a certain width, which uniformly irradiates the surface of the fluorescent gradual conversion sheet 2. The black-and-white area array CCD is electrically connected to a computer 4 through a data line, and the computer 4 is installed with data processing software. The visible light intensity image 41 can be displayed on the screen of the computer 4. The visible light refers to the part of the visible light emitted by the fluorescent ink excited by the ultraviolet light and received by the black-and-white area array CCD through the fluorescent gradual conversion sheet 2.

[0134] The excitation curve is determined. The excitation curve refers to the excitation curve of the corresponding excitation unit measured by the light intensity of the light emitting unit 411 changing with the wavelength of the ultraviolet light, which is not the intensity change of a certain emission wavelength in the usual sense, because the black-and-white area array CCD cannot identify the wavelength.

[0135] The determination process is as follows:

[0136] Firstly, the visible light intensity image 41 of the fluorescent gradual conversion sheet 2 is evenly divided into 512 units on the screen of the computer 4, and each partition is evenly divided into 8x8=64 units, which are transmission units. The data processing software calculates the visible light intensity of each transmission unit.

[0137] The monochromator 6 scans and outputs the single wavelength ultraviolet light of the standard ultraviolet light one by one, while the black and white area array CCD takes the visible light intensity image 41 of the single wavelength ultraviolet light irradiated on the fluorescent gradual change conversion sheet 2 in each wavelength, and records the light intensity of each transmission unit;

[0138] As described above, the light intensity of each transmission unit changes with the wavelength. Since the proportions and densities of the fluorescent inks of the fluorescent layers A, B and C of the excitation unit on the fluorescent gradual change conversion sheet 2 corresponding to each transmission unit are different, the 512 emitted visible light intensity curves with the wavelength are different, and there is no linear relationship between them;

[0139] The light intensity of each transmission unit changes with the wavelength. Since the proportions and densities of the fluorescent inks of the fluorescent layers A, B and C of the excitation unit on the fluorescent gradual change conversion sheet 2 corresponding to each transmission unit are different, the 512 emitted visible light intensity curves with the wavelength are different, and there is no linear relationship between them;

[0140] In another embodiment, in order to increase the accuracy and accuracy, some auxiliary devices such as the lens group 7 and the monochromator 6 can be added. The concentration of the fluorescent ink layer A 22 is linearly and continuously changed, the concentration of the fluorescent ink layer B 23 is changed in a stepwise manner in the direction perpendicular to the change of the fluorescent ink layer A 22, and the concentration of the fluorescent ink layer C 24 is uniform but different in the eight partitions of the fluorescent gradual change conversion sheet 2. The change of the fluorescent ink layer A 22, the fluorescent ink layer B 23 and the fluorescent ink layer C 24 in the three perpendicular directions X, Y and Z (the three coordinates X, Y and Z are commonly used in mathematics, and will not be described in detail in this scheme) ensures that the relative proportions of the first fluorescent material of the fluorescent ink layer A 22, the second fluorescent material of the fluorescent ink layer B 23 and the third fluorescent material of the fluorescent ink layer C 24 are different. In actual application, the fluorescent ink layer A 22, the fluorescent ink layer B 23 and the fluorescent ink layer C 24 combined with the gradual change image generated by the image sensing device 3 can be linearly and continuously changed, or can be changed in a stepwise manner, or can use more than three fluorescent inks to form a fluorescent gradual change conversion layer.

[0141] The above examples illustrate the specific UV spectrum measuring method of the present application, and in practice different sizes and pixel numbers of the black-and-white area array CCD can be used in different applications; the size of the fluorescent gradual transition conversion sheet 2 also changes accordingly, and the gradually transitioned visible light intensity image 41 can be various, as long as the excitation spectrum curves of the divided excitation units are different and have no linear relationship.

[0142] For the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts are referred to the part of the method embodiment.

[0143] Each embodiment in the present specification is described in a progressive manner, and each embodiment focuses on the difference from other embodiments, and the same and similar parts between each embodiment are referred to each other.

[0144] Although the preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be interpreted as including all the changes and modifications of the preferred embodiments and falling within the scope of the embodiments of the present application.

[0145] Finally, it should be noted that in this document, the relationship terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or terminal device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or terminal device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or terminal device including the element.

[0146] The above describes in detail the UV spectrum measuring method and the UV spectrum measuring device provided by the present application, and the principle and implementation manner of the present application are described by using specific examples in this document. The above embodiment description is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation manner and application range will be changed, and the above description should not be understood as limiting the present application.

Claims

1. A method of measuring ultraviolet spectrum, characterized by, The application relates to a fluorescence gradual change conversion device and a method for measuring the spectrum of ultraviolet light. The fluorescence gradual change conversion device converts the acquired ultraviolet light to be measured into visible light and transmits the visible light to an image sensing device; The method comprises the following steps: acquiring the excitation spectrum curve of the fluorescence gradual change conversion device; specifically, a monochromator is used to uniformly irradiate single-wavelength ultraviolet light of different wavelengths in a standard ultraviolet light source to the fluorescence gradual change conversion device in sequence; a visible light intensity image of the single-wavelength ultraviolet light is generated in a data processing device; the visible light intensity image is divided into N transmission units, and the luminous intensity of the transmission units is calculated; the luminous intensity variation curve of the transmission units with the ultraviolet wavelength is generated according to the luminous intensity variation of the transmission units; and the excitation spectrum curve is obtained by comparing the luminous intensity variation curve of the N transmission units with the emission spectrum of the standard ultraviolet light source; The image sensing device converts the visible light into a visible light intensity image and transmits the visible light intensity image to a data processing device; According to the visible light intensity image acquired by the data processing device, the excitation spectrum curve of the fluorescence gradual change conversion device is combined, and the spectrum of the ultraviolet light to be measured is calculated according to a preset reconstruction algorithm.

2. The method of claim 1, wherein, The excitation spectrum curve is obtained by comparing the luminous intensity variation curve of the N transmission units with the emission spectrum of the standard ultraviolet light source, and the method comprises the following steps: The excitation rate alpha n of a more dense wavelength position is obtained by an interpolation method.

3. The method of claim 2, wherein, The image sensing device converts the visible light into a visible light intensity image and transmits the visible light intensity image to a data processing device, and the method comprises the following steps: The visible light transmitted by the fluorescence gradual change conversion sheet which is preset to be continuously linearly changed, nonlinearly changed or stepwisely changed is acquired; The visible light is converted into a visible light intensity image by the image sensing device which is composed of a black-and-white area array CCD or a black-and-white area array CMOS; The visible light intensity image is transmitted to the data processing device.

4. The method of claim 3, wherein, The spectrum of the ultraviolet light to be measured is calculated according to the visible light intensity image acquired by the data processing device and a preset reconstruction algorithm, and the method comprises the following steps: The visible light intensity image is divided into N luminous units; The data processing device acquires the visible light intensity image, and divides the fluorescence gradual change conversion device into N excitation units according to the N luminous units; The luminous intensity P of the luminous unit is calculated; N uniformly spaced wavelength positions in the excitation unit are selected, and an equation containing the incident ultraviolet light intensity xn corresponding to the wavelength position is established according to the luminous intensity P and the excitation rate alpha n corresponding to the wavelength position; N equations containing the luminous intensity Pm of the incident ultraviolet light intensity xn are established, and the spectrum of the ultraviolet light to be measured is calculated.

5. The method of claim 4, wherein, The excitation rate alpha n of a more dense wavelength position is obtained by an interpolation method. The equation P = x1alpha1 + x2alpha2 + … + xnalpha n + … + xNalphaN is established.

6. The method of claim 5, wherein, ​ The matrix equation system is established: Pm= x1αm-1+ x2αm-2+…+ xnαm-n+…+ xNαm-N.

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