Narrowband multispectral generation method and system

Abstract

The invention relates to a narrow-band multispectral generation method and system. The method comprises the steps that a wide-spectrum light source is obtained through a visible light source, a near-infrared source and a near-ultraviolet source; by adjusting the output energy of the broadband spectrum light source and designing a light propagation path, light is converged to the maximum extent, and the converged light is arranged, aligned and output; an optical filter array is adopted to filter out the wide spectrum, and a narrow-band spectrum is obtained and output; narrow-band spectrums of different wavebands are obtained by automatically switching the optical filter array; a computer is used for controlling the output amplitude and the output time of the wide-spectrum light source. The multi-band narrow-band spectrum can be rapidly obtained, and the multi-band narrow-band spectrum switching device has the advantages of being high in narrow-band spectrum resolution, wide in spectrum bandwidth coverage range, high in switching speed, adjustable in spectrum energy, low in cost and the like.

Description

Technical Field

[0001] The present invention relates to a method and system for generating narrowband multi-spectra, belonging to the fields of optical technology, automatic control, and materials, and specifically applied to fields such as multi-spectral imaging, spectral analysis, industrial inspection, environmental monitoring, medical imaging, and machine vision. The present invention can achieve the output of multiple narrowband spectra, and has the characteristics of high narrowband spectral resolution, spectral stability, narrow passband bandwidth, wide spectral coverage range, etc., and has broad application prospects. Background Art

[0002] With the wide application of spectral technology in fields such as medical imaging, remote sensing, environmental monitoring, industrial inspection, machine vision, and artificial intelligence, the demand for narrowband spectra is increasing day by day. Existing narrowband spectrum generation methods generally have problems such as complex processes, slow band switching speed, wide spectral passband bandwidth, limited wavelength adjustment range, and high costs. Especially for multi-spectral systems that need to cover both visible and non-visible light bands simultaneously, how to effectively, accurately, and low-costly generate narrowband multi-spectra remains a technical problem.

[0003] Existing narrowband spectrum generation systems usually adopt nano-devices and liquid crystal modulation technology. However, with the increasing demand for the accuracy, stability, and wider wavelength coverage range of narrowband spectra, the existing technologies often have the following deficiencies: First, the production process of narrowband spectrum devices is relatively complex and costly. Due to the limitations of material and process stability, it is difficult for existing technologies to achieve highly consistent narrowband spectra; for example, Patent CN110146949A proposes an FP-type narrowband spectrum filter structure based on a fixed dielectric layer thickness, which requires complex processes such as deposition and etching to prepare, and has extremely high process requirements, resulting in high production costs and technical thresholds. Second, the liquid crystal modulation technology has certain limitations in spectral resolution. The passband bandwidth of liquid crystal modulation is relatively wide, and the wavelength adjustment range is limited, especially in the deep ultraviolet band, which makes it unable to meet the requirements of high-precision narrowband spectrum adjustment. Finally, the narrowband spectrum methods implemented by the above two methods generally have high costs, which limits their practical application and promotion.

[0004] Therefore, there is an urgent need for a low-cost, high-precision, wide coverage band range, and easily available narrowband spectrum generation system and method; this system needs to be able to provide high-precision and high-stability narrowband spectra, and also have the characteristics of adjustable bandwidth of narrowband spectra, wide wavelength coverage band range of narrowband spectra, simple production and processing technology, low cost, etc., and be able to achieve flexible configuration of spectral band combinations. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a method and system for generating narrowband multi-spectra, and the technical solutions adopted are as follows:

[0006] The present invention provides a narrow-band multi-spectrum generation method and system, the system and method comprising:

[0007] A wide spectrum light source is provided, the band of the wide spectrum light source is the full band of the visible light band and the non-visible light band, or one of them is selected; it covers the full spectrum band of the required narrow-band spectrum band, and the wide spectrum light source has a large power to ensure that there is sufficient spectral energy in a single narrow-band spectrum band;

[0008] The energy output of the wide-spectrum light source is controlled by a computer program, the energy amplitude of the narrow-band spectrum is adjusted, and the continuous output time of the narrow-band spectrum is controlled;

[0009] The light emitted by the wide spectrum light source is converged by a conical reflector, and then the light is adjusted by an optical element to obtain a parallel beam of a certain caliber;

[0010] A plurality of narrow-band spectral filters are combined into a filter array, the transmitted narrow-band bands of which are superimposed to cover the combined band of the visible light band and the non-visible light band, or a part of the bands therein, and the filter array is evenly arranged in a circle;

[0011] A circular rotating platform is designed to provide rotational power. The platform rotation is controlled by a motor and a reducer to obtain precise rotation speed and angle, so that the filter array and the wide spectrum light source are aligned parallel to each other and the parallel straight path of the light beam is ensured.

[0012] The energy amplitude, duration, platform rotation angle and dwell position of the wide-spectrum light source are synchronously controlled to obtain a narrow-band spectrum and complete the switching of the narrow-band spectrum.

[0013] Preferably, the wavelength band of the wide spectrum light source is a visible light band, or a spectrum band obtained by combining a visible light source with a non-visible light source:

[0014] The visible light band of 380nm to 780nm uses multiple LED chips, the band of 760nm to 1100nm uses near-infrared chips, and the band of 300nm to 400nm uses ultraviolet chips. A continuous wide-spectrum light source is obtained through the combination of multiple chips;

[0015] Furthermore, the light beam emitted by the wide spectrum light source is converged by using a conical reflector, and then the converged light beam is adjusted by using an optical element, including:

[0016] The conical reflector converges the light emitted by the wide-spectrum light source and emits it to one side of the light source. The light output angle is ≤5°, and the position of the wide-spectrum light source remains unchanged.

[0017] The optical elements used consist of a lens group, which adjusts the light beam at the light outlet of the conical reflector. The apertures of adjacent lenses are close to the maximum aperture of the reflector. By adjusting the distance between lenses A and B, light can be obtained to the maximum extent, and the divergent light is adjusted into a parallel light beam with a small aperture. The adjustment function is:

[0018] D = 2ftan(θ max ),

[0019] where D is the diameter of the parallel light beam, f is the focal length of the conical reflector, and θ max is the maximum incident angle of the broadband light source;

[0020] The diameter of the parallel light beam after being adjusted by the combination of optical lenses A and B is not greater than 50 mm. The function of the adjustment distance and the final diameter of the parallel light is:

[0021]

[0022] where D final is the final output diameter of the parallel light beam, D B is the diameter of lens B, d AB is the distance between lens A and lens B, and f B is the focal length of lens B.

[0023] Preferably, multiple narrow-band spectral filter plates are combined into a filter array, and the transmission bands of which cover the visible light band and the non-visible light band after being superimposed. The filter array is arranged uniformly in a circle on a cylinder, and the cylinder is fixed on a rotating table, including:

[0024] The spectral bandwidth of the narrow-band filter is 1 nm to 10 nm, and the diameter is not less than 20 mm. The function of the spectral transmission bandwidth is:

[0025]

[0026] where λ total is the total number of narrow-band spectra, I out (λ i ) is the central bandwidth of the spectrum after passing through the filter, I in (λ) is the width of the incident spectrum, and i is the ordinal number in the total number of spectra.

[0027] The filter is parallel and consistent with the center line of the light outlet surface of the broadband light source. The broadband light source is located inside the cylinder arranged in a circle, and the cylinder is connected to the rotating table, while the broadband light source is not connected to the rotating table.

[0028] Furthermore, to complete the switching of different narrow-band spectra, the position of the filter is switched by controlling the rotating table by a computer, and the rotation speed and angle of the rotating table are controlled by a program to achieve the parallel alignment of the filter and the broadband light source. The corresponding rotation angle and speed are:

[0029]

[0030] Among them, θ i is the rotation angle corresponding to the i-th narrowband spectral band, and θ 0 is the initial position corresponding to this rotation, and i total is the total number of narrowband spectra.

[0031] Control the spectral output amplitude and output duration of the broadband light source through a computer program, and at the same time control the operating speed and angle of the turntable.

[0032] The embodiments of the present invention have at least the following beneficial effects:

[0033] A narrowband multi-spectral generation method and system proposed by the present invention obtain a small-diameter parallel broadband light beam by acquiring a broadband light source and processing it through an optical module, and obtain a narrowband spectral set through a narrowband filter array; the narrowband spectra obtained by this method have the characteristics of high precision, strong stability, and a wide coverage range of narrowband spectral bandwidths.

[0034] A narrowband multi-spectral generation method and system proposed by the present invention combine a visible spectrum and a non-visible spectrum for the broadband light source, and use an automatic rotation platform to complete spectral switching, improving the accuracy and stability of the narrowband spectrum, and at the same time reducing the production process and production cost of narrowband spectrum generation.

[0035] In the present invention, the above-mentioned various technical solutions can be combined with each other to achieve more preferred combination schemes. Other features and advantages of the present invention will be described in the subsequent specification. The objectives and other advantages of the present invention can be achieved and obtained through the content specifically pointed out in the specification and the drawings. Description of the Drawings

[0036] Figure 1 is a flowchart of a narrowband multi-spectral generation method provided by an embodiment of the present invention;

[0037] Figure 2 is a system diagram of a narrowband multi-spectral generation system provided by an embodiment of the present invention. Detailed Embodiments

[0038] In order to further elaborate on the technical means and effects adopted by the present invention to achieve the intended invention objectives, the preferred embodiments of the present invention will be specifically described below with reference to the drawings. Among them, the drawings form a part of this application and are used together with the embodiments of the present invention to explain the principles of the present invention, and are not used to limit the scope of the present invention.

[0039] Method Embodiment:

[0040] A specific embodiment of the present invention discloses a method for generating narrowband multi-spectra, which realizes obtaining multiple narrowband spectra covering visible and non-visible light bands, and automatic switching can be performed between the multiple narrowband spectra. As Figure 1 shown, the method includes:

[0041] Step S1, set the wide-spectrum light source band to the visible light band or the non-visible light band, or a wide spectrum obtained by combining a visible light source and a non-visible light source.

[0042] First of all, it should be noted that the set wide-spectrum light source can be individually set and adjusted according to needs. The spectrum of the generated wide-spectrum light source needs to be continuously distributed in the interval. This flexible selection can not only meet the actual needs but also reduce costs; in the preferred embodiment of the present invention, it is set as a continuous wide spectrum of visible light and non-visible light combination.

[0043] Secondly, the power of the wide-spectrum light source is set to not less than 400W and is equipped with a heat dissipation device; a large enough power provides enough spectral energy for the narrowband spectrum to ensure that the narrowband spectrum energy in the selected band is not less than 0.5W / m 2 .

[0044] Then, the wide-spectrum light source uses a computer-controlled chip, and the output amplitude and output duration of the wide-spectrum light source are controlled by a program.

[0045] Step S2, use a conical reflector to converge the light emitted by the wide-spectrum light source, and then use two lenses A and B to adjust the light. Lens A converges the light reflected by the reflector. Utilizing the light focusing characteristics of the lens, lens B is used to minimize the output diameter of the light to obtain a parallel beam with a diameter less than 50mm.

[0046] The conical reflector converges the wide-spectrum light to the light output side of the light source. The light output angle of the reflector ≤5°. The position of the wide-spectrum light source remains unchanged all the time. The light adjustment function of the reflector is:

[0047] D = 2ftan(θ max ),

[0048] where D is the diameter of the parallel light, f is the focal length of the parabolic mirror, and θ max is the maximum incident angle of the light source;

[0049] A lens group is used to adjust the light at the light output of the reflector. The aperture of lens A is close to the maximum aperture of the reflector. Adjust the position of lens B relative to lens A to obtain the light to the maximum extent, and adjust the divergent light into a small-aperture parallel light. The diameter of the parallel light after being adjusted by the combination of optical lenses A and B is 25mm. The function of the adjustment distance and the final parallel light diameter is:

[0050]

[0051] Among them, D final is the diameter of the final output parallel light, D B is the diameter of lens B, d AB is the distance between lens A and lens B, f B is the focal length of lens B.

[0052] Step S3, preferably, a plurality of narrow-band spectral filter plates are combined into a filter array, and the transmission bands thereof are superimposed to cover the visible light band. The filter plate array is arranged uniformly in a circle and fixed on an acrylic cylinder with a thickness of 30 mm; the generated narrow-band spectral function includes:

[0053] The spectrum of the filter plate has a central bandwidth of 10 nm and a diameter of not less than 25 mm. The narrow-band spectral bandwidth passing function is:

[0054]

[0055] Among them, λ total is the total number of narrow-band spectra, I out (λ i ) is the spectral width after passing through the filter plate, I in (λ) is the incident spectral width, and i is the ordinal number in the total number of spectra.

[0056] Preferably, the filter plate array is arranged uniformly in a circle on the acrylic cylinder, and its connection with the cylinder is a detachable connection. Different filter plate groups with different bands and bandwidths can be replaced according to needs, and it is at the same height as the light-emitting surface of the broadband light source; the broadband light source is located inside the cylinder, and the acrylic cylinder where the filter plate array is located is connected to the rotating table to jointly complete the switching of different filter plates.

[0057] Step S4, control the switching of the filter plate array. Preferably, a circular rotating table is designed to be connected to the filter plate cylinder in S3, and the rotation of the platform is controlled by a motor and a reducer to obtain accurate rotation speed and angle, so as to achieve the parallel alignment of the filter plate and the broadband light source position. The corresponding rotation angle and speed are:

[0058]

[0059] Among them, θ i is the rotation angle corresponding to the i-th band, θ 0 is the initial position corresponding to this rotation, i total is the total number of narrow-band spectra.

[0060] Step S5: Use a computer to write a Python program to control the program, which controls the energy amplitude and output duration of the wide-spectrum light source respectively, and simultaneously controls the rotation speed and angle of the rotary table, and records the running position and the output spectral parameters.

[0061] System embodiment

[0062] Another embodiment of the present invention discloses a narrowband multi-spectral generation system, including:

[0063] A wide-spectrum light source module for obtaining a spectral source with a wide enough bandwidth and a certain spectral energy amplitude, including visible light sources and non-visible light sources.

[0064] An optical module includes a conical reflector for converging the divergent light of the wide-spectrum light source, an optical lens group, an optical parallel fixing member, etc.; the conical reflector converges the large-angle spectrum emitted by the light source to one side of the light source to form a small-aperture light-emitting surface; the optical lens group sorts out the light converged by the conical reflector, and the light is sorted into a small-aperture parallel light source to converge the spectral energy to the maximum extent.

[0065] A filter group module, which consists of multiple filters and a filter fixing circular cylinder; the filters complete the work of filtering the spectrum of specific wavelengths, and the cylinder fixes the filters and ensures their uniform distribution; the module completes the output of the spectrum emitted by the wide-spectrum light source as a narrowband spectrum.

[0066] A rotary table, including a stepping motor, a reducer, a controller, a metal platform and a support; the motor and the reducer form a power unit, and the controller completes the control of the start, stop and speed of the motor, and the entire rotary table formed completes the position switching of different filters.

[0067] A control module, which consists of a computer and a control program; the program controls the on / off, spectral amplitude and output spectral duration of the wide-spectrum light source; the program synchronously controls the rotation speed and angle of the rotary table to continuously switch the output of different narrowband spectral wavelengths according to actual needs.

[0068] Preferably, the wide-spectrum light source module has one of the visible spectrum, near-infrared, and near-ultraviolet bands, or can be a combination of multiple bands.

[0069] The optical module uses a conical reflector to converge the wide spectrum, and the lens group corrects the size of the output light spot, and finally outputs parallel light with a small diameter. The diameter of the adjusted light-emitting surface is 25 mm.

[0070] Preferably, after the wide spectrum is adjusted by the optical module, it enters the filter to filter out the unnecessary bands and pass through the required band spectrum to output a narrowband spectrum; the filter group is circumferentially distributed on the cylinder, and the cylinder is connected to the rotary table.

[0071] Preferably, the filter slice switching method is a cylindrical rotation type. The broadband light source is placed inside the cylinder, and the rotation action is completed by a rotating table, which drives the position switching of the filter slice while keeping the position of the broadband light source stationary. The rotating table switches the filter slice at the i 0 th position to the i position and aligns the filter slice with the broadband light source. The rotation action is controlled by a computer program, and the rotation speed and angle can be set, and the switching can be completed between any positions to complete the narrowband spectrum output.

[0072] Compared with the prior art, the narrowband multi-spectral generation method and system proposed by the present invention, firstly, obtain a broadband spectrum covering visible light and non-visible light by setting the composition mode of the broadband light source to ensure the stability and reliability of the spectrum source. Secondly, use a filter slice group to obtain high-precision and stable narrowband spectrum output; then, complete the spectrum switching of different bands through the cylindrical rotation method, which has the characteristics of high stability and high precision; finally, control the start, stop, and amplitude of the broadband light source through a computer program; synchronously control the rotation angle and speed of the rotating platform through a computer program to complete the output of the required narrowband spectrum. This method and system reduce the process difficulty of generating narrowband spectra, improve the precision and stability of narrowband spectra, and reduce the cost of obtaining high-quality narrowband spectra.

[0073] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A narrowband multi-spectrum generation method and system, characterized in that: The system comprises: a combined wide-spectrum light source in the visible and non-visible light bands, for providing an initial wide-spectrum output; an optical component, comprising a conical reflector, for adjusting the light beam dispersed by the wide-spectrum light source into parallel light, and further adjusting the wide-diameter parallel light into small-diameter parallel light; and an electric rotating platform, comprising a circular cylinder and a rotating platform for supporting the spectral filter array, and enabling the filter array to be switched, thereby realizing narrow-band spectrum switching of different wavelengths.

2. The narrowband multi-spectrum generation method and system according to claim 1, characterized in that: The optical assembly includes: a conical reflector for focusing the broad spectrum light into a parallel beam, and a collimating optical element for further adjusting the diameter of the parallel beam so that the diameter of the parallel beam meets the requirements, and the generated beam diameter is: D = 2ftan(θmax), Where D is the parallel beam diameter, f is the focal length of the parabolic mirror, θ max is the maximum incident angle of the broad spectrum light source.

3. The narrowband multi-spectrum generation method and system according to claim 1, characterized in that: The spectral filter array includes a plurality of spectral filters of different types. The central wavelength coverage range of the filter array is 300nm to 1100nm, and the bandwidth of each spectral filter is between 1nm and 10nm. The narrowband spectral bandwidth coverage function is: Among them, λ total is the narrowband spectrum summary, I out (λ i ) is the light intensity after passing through the filter, I in (λ) is the incident light intensity.

4. The narrowband multi-spectrum generation method and system according to claim 1, characterized in that: The switching of the spectral filter array is driven by electric rotation. The electric rotating platform is connected to a computer control system and can control the rotation speed, rotation angle and switching time of the spectral filter array according to a preset program.

5. The narrowband multi-spectrum generation method and system according to claim 1, characterized in that: The wide spectrum light source is a light emitting diode chip light source, a xenon lamp or other visible light source, and infrared, ultraviolet or other light sources suitable for emitting a wide spectrum in combination.

6. The narrowband multi-spectrum generation method and system according to claim 1, characterized in that: The system further includes a temperature control device for controlling the temperature of the wide spectrum source, the spectrum filter, the motor and the reducer to prevent the output stability of the spectrum light source and the optical performance of the spectrum filter from being affected by temperature fluctuations, thereby ensuring the stable operation of the entire system.

7. The narrowband multi-spectrum generation method and system according to claim 1, characterized in that: The optical adjustment element in the optical assembly can adjust the diameter of the parallel light within a certain range, the adjustment range is 10mm to 100mm, to meet different spectral resolution requirements, and the final output beam diameter is: Where D0 is the initial beam diameter; f0 is the focal length of the lens; and z is the distance between the beam and the lens.

8. The narrowband multi-spectrum generation method and system according to claim 1, characterized in that: The electric rotating table is equipped with a cylinder, and the filters are evenly distributed on the cylinder; the rotating table supports forward and reverse rotation, so that the spectral filter array can be freely switched in two directions, thereby achieving faster wavelength switching and control.

9. The narrowband multi-spectrum generation method and system according to claim 1, characterized in that: The control system uses Python programming to communicate with the hardware, and the program controls the platform to rotate and stop operation to complete the position switching of the filter array.

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