TW201321727A - Spectrum measurement systems and methods for spectrum measurement - Google Patents

Abstract

A spectrum measurement system is provided, includes a first afocal system, a first grating, a second grating and a second afocal system. The first afocal system receives an incident light from the object to parallel the incident light with a system normal light. The first grating diffracts the incident light to different wavelength lights with different emergent angles. The second afocal system sifts a predetermined wavelength from the lights outputted from the first grating to output a diffractive light having the predetermined wavelength. The second grating eliminates optical path difference made from the first grating. The third afocal system receives the diffractive light from the second grating to output a monochromatic light parallel with the system normal light.

Description

Spectral measurement system and spectral measurement method

The disclosure relates to a spectral measurement system, and more particularly to a global spectral measurement system.

Due to industrial advances, industrial products are becoming more diverse, making the spectrum of measurement products no longer limited to single-point measurements. For example, because of the durability, long life, light weight, low power consumption and the absence of harmful substances (such as mercury), lighting technology using light-emitting diodes has become a lighting industry and semiconductor. The future of the industry is a very important development direction. In general, the light-emitting diode system is widely used in white light illumination devices, indicator lights, vehicle signal lights, automotive headlights, flashlights, backlight modules for liquid crystal displays, light sources for projectors, outdoor display units, and the like.

Since the optical detection technology of the light-emitting diode mostly adopts single-point measurement, when the global spectrum measurement technology is adopted, the conventional technique uses a liquid-crystal tunable filter (LCTF) or a brain tomography image. Computed tomographic imaging spectrometer (CTIS), but both of them have the problem of insufficient spectral resolution. Therefore, there is a need for a spectral measurement system and a spectral measurement method that take into account the spectral resolution and the characteristics of the global image acquisition to measure the spectrum of the analyte.

In view of the above, the present disclosure provides a spectral measurement system, including: a first non-focusing module for receiving an incident light emitted by an object to be tested, such that the incident light is parallel to a system normal; a grating for diffracting incident light of different wavelengths into different exit angles; a second non-focusing module from the first grating; and a second non-focusing module for receiving output from the second grating The light is diffracted to output a monochromatic light parallel to the normal of the system.

The disclosure also provides a spectral measurement method, which is suitable for a spectral measurement system. The spectral measurement system includes a first non-focusing module, a second non-focusing module, a third non-focusing module, and a first The grating and the second grating, the spectral measurement method comprises: receiving, by the first non-focusing module, an incident light emitted by the object to be tested, so that the incident light is parallel to a system normal; by the first grating and the first The second non-focusing module selects a specific wavelength from the incident light output by the first non-focusing module, so that the second non-focusing module outputs only one diffracted light having a specific wavelength; and the first grating and the second The grating and the second non-focusing module eliminate the optical path difference caused by the first grating; and receive the diffracted light output from the second grating by the third non-focusing module, so that the output is parallel to the system normal Light.

The above and other objects, features and advantages of the present invention will become more apparent and understood.

Figure 1 is an embodiment of the spectral measurement system of the present disclosure. As shown in FIG. 1, the spectral measurement system 100 includes afocal systems 110, 120, and 130, gratings G1 and G2, and a planar light detector 140. For example, the non-focusing module 110 is configured to receive an incident light C1 emitted by the object to be tested 150 such that the incident light C1 is parallel to the normal line NL of the system. The grating G1 is used to diffract light of different wavelengths of the incident light C1 to different angles, and filters a specific wavelength through the lens L3 and the aperture A2 to output only the diffracted light C2 having a specific wavelength. The gratings G1, G2 and the lenses L3, L4 and L5 are used to eliminate the optical path difference between the diffracted lights C2 from different positions of the points P1, P2 and P3, for example, the direction and angle of rotation of the grating G2 and the direction in which the grating G1 changes. Same as the angle to compensate for the optical path difference caused by the grating G1. The non-focusing module 120 is configured to receive the diffracted light C2 output from the grating G2 to output a monochromatic light C3 parallel to the system normal NL. The non-focusing module 130 (including the aperture A2 and the lenses L3, L4 and L5) is disposed between the gratings G1 and G2 for changing the track paths from different positions of the points P1, P2 and P3 and increasing the spectral resolution by the aperture A2.

The control unit 160 is disposed in the planar light detector 140 for controlling the grating G1 such that the incident angle of the incident light C1 and the grating G1 corresponds to a specific wavelength. The control unit 160 also controls the grating G2 such that the angle at which the grating G2 rotates is the same as the angle at which the grating G1 changes, so as to compensate the optical path difference between the diffracted lights C2 from the points P1, P2 and P3 via the lenses L3, L4 and L5. In some embodiments, the control unit may also be disposed outside of the photodetector 140, but is not limited thereto. In the disclosed embodiment, the gratings G1 and G2 are parallel to each other, and the gratings G1 and G2 are parallel even after the gratings G1 and G2 are rotated. The planar light detector 140 is configured to receive the monochromatic light C3 to record the intensity of the monochromatic light C3. In the embodiment of the disclosure, the surface light detector 140 may be a charge-coupled device (CCD), and the different wavelength images of the object to be tested 150 are imaged and recorded by a snapshot. User analysis.

In detail, the non-focusing module 110 includes a lens L1 and L2 and an aperture A1. The lens L1 is for receiving incident light C1, and the lens L2 is for emitting incident light C1 in parallel. Aperture A1 is disposed between lenses L1 and L1 to improve spectral resolution to avoid cross talk.

The non-focusing module 130 is disposed between the gratings G1 and G2 for changing the track paths from different positions of the points P1, P2 and P3 and increasing the spectral resolution by the aperture A2. The non-focusing module 130 includes lenses L3, L4, and L5 and an aperture A2. The lens L3 is for receiving the diffracted light C2. The lens L4 is used to change the trace of the diffracted light C2. Aperture A2 is disposed between lenses L3 and L4 to improve spectral resolution. The lens L5 is for outputting the diffracted light C2 in parallel.

The non-focusing module 120 includes lenses L6 and L7. The lens L6 is for receiving the diffracted light C2, and the lens L7 is for changing the trace of the diffracted light C2. In some embodiments, the non-focusing module 120 also has an aperture A3 (not shown) disposed between the lenses L6 and L7 for improved spectral resolution.

Figure 2 is a schematic diagram of one of the gratings G1 of the present disclosure. As shown in Fig. 2, the grating G1 is used to filter the incident light C1 by a specific wavelength of light, where θi is the incident angle, θd is the diffraction angle, and Δθ is the angle between the diffracted light C2 and the system normal NL. The relationship between θi and θd can be expressed by Equation 1 and Equation 2:

θ d =Δθ-θ i ----Form 2

Where d is the grating stripe pitch, and the angles Δθ and d are constant values. Therefore, by changing the incident angle θi, it is possible to filter out light of a specific wavelength λ.

Fig. 3 is a graph showing the relationship between the incident angle θi, the diffraction angle θd, and the angle Δθ of the present disclosure. As shown in FIG. 3, when the visible light image of the test object 150 (wavelength is 374 nm to 781 nm) is measured and the angle Δθ is maintained at a certain value (for example, 40 degrees), the incident angle θi of the spectral measurement system 100 is The diffraction angle θd is not deflected by more than 90°, so that in the visible light range, the disclosed embodiment can sufficiently measure the image of each wavelength of the object to be tested 150.

FIG. 4 is an image of an embodiment of the present disclosure for illustrating an image of the object to be tested 150 obtained by the spectral measurement system 100. As shown in FIG. 4, the image 400 is quite sharp and has no aberrations, so the spectral measurement system 100 is well suited for measuring large areas of the object to be tested.

Figure 5 is a flow chart of one of the spectral measurement methods of the present disclosure. As shown in the figure, the spectral measurement method includes the following steps.

In step S51, the incident light C1 emitted by the object to be tested 150 is received by the non-focusing module 110 such that the incident light C1 is parallel to the system normal NL. In step S52, the light of different wavelengths of the incident light C1 is diffracted into different angles by the grating G1, and the diffracted light C2 having a specific wavelength is filtered through the lens L3 and the aperture A2. In step S53, the optical path differences of the diffracted lights at different positions of the same plane are eliminated by the gratings G1, G2 and the non-focusing module 130 (for example, the lenses L3, L4, and L5) (for example, the same planes are from points P1, P2, and P3, respectively). Light). In step S54, the diffracted light C2 is received by the non-focusing module 120 to output monochromatic light C3 parallel to the system normal NL.

In summary, by means of the non-focusing modules 110, 120 and 130 and the gratings G1 and G2, the points P2, P3 (as shown in Fig. 1) away from the optical axis center point P1 can be made to be incident parallel without deviation. Points P5 and P6 (as shown in Fig. 1), and the image of the object to be tested 150 at the points P2 and P3 is not deformed, so that the effect of the global image capturing is achieved.

The features of many embodiments are described above to enable those of ordinary skill in the art to clearly understand the form of the specification. Those having ordinary skill in the art will appreciate that the objectives of the above-described embodiments and/or advantages consistent with the above-described embodiments can be accomplished by designing or modifying other processes and structures based on the present disclosure. It is also to be understood by those skilled in the art that <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt;

100. . . Spectral measurement system

G1~G2. . . Grating

L1~L7. . . lens

110, 120, 130. . . No focus module

140. . . Surface light detector

150. . . Analyte

160. . . control unit

C1. . . Incident light

C2. . . Diffracted light

C3. . . monochromatic light

A1, A2. . . aperture

P1~P6. . . point

NL. . . System normal

Θi. . . Incident angle

Θd. . . Diffraction angle

△θ. . . angle

400. . . image

Figure 1 is an embodiment of the spectral measurement system of the present disclosure;

Figure 2 is a schematic view of one of the gratings G1 of the present disclosure;

Figure 3 is a diagram showing the relationship between the incident angle θi, the diffraction angle θd, and the angle Δθ of the present disclosure;

FIG. 4 is an image of an embodiment of the present disclosure for illustrating obtaining an image of the object to be tested 150 by using the spectral measurement system 100;

Figure 5 is a flow chart of one of the spectral measurement methods disclosed herein.

100. . . Spectral measurement system

G1~G2. . . Grating

L1~L7. . . lens

110, 120, 130. . . No focus module

140. . . Surface light detector

150. . . Analyte

160. . . control unit

C1. . . Incident light

C2. . . Diffracted light

C3. . . monochromatic light

A1, A2. . . aperture

P1~P6. . . point

NL. . . System normal

Claims (10)

A spectral measurement system includes: a first non-focusing module for receiving an incident light emitted by a test object such that the incident light is parallel to a system normal; a first grating for different The incident light of the wavelength is diffracted into different exit angles; a second non-focusing module filters a specific wavelength from the incident light output by the first grating, so that the second non-focusing module only outputs a diffracted light of the specific wavelength to the second grating; a second grating and a non-focusing module for eliminating the optical path difference of the diffracted light; and a third non-focusing module for receiving the second The diffracted light output by the grating is such that a monochromatic light parallel to the normal of the above system is output. The spectral measurement system of claim 1, comprising a control unit for adjusting the first grating such that the incident light output from the first non-focusing module and the first grating are incident. The angle corresponds to the specific wavelength described above. The spectral measuring system of claim 2, wherein the control unit controls the second grating such that a direction and an angle of rotation of the second grating are the same as a direction and an angle of the first grating to compensate for The optical path difference caused by the first grating. The spectral measuring system of claim 3, comprising a one-sided photodetector for receiving the monochromatic light to record the intensity of the monochromatic light. The spectral measurement system of claim 4, wherein the first non-focusing module comprises: a first lens for receiving the incident light; and a second lens for outputting the incident light in parallel. And the first grating; and a first aperture disposed between the first lens and the second lens for improving spectral resolution. The spectral measurement system of claim 5, further comprising a third non-focusing module disposed between the first grating and the second grating, wherein the third non-focusing module comprises: a third lens for receiving the diffracted light outputted from the first grating; a fourth lens for changing a trace of the diffracted light outputted from the third lens; a second aperture disposed at the Between the third lens and the fourth lens, the spectral resolution is improved, wherein the third lens and the second aperture filter a specific wavelength from the light output by the first grating, so as to output only the specific wavelength. The diffracted light; and a fifth lens for outputting the diffracted light in parallel to the second grating. The spectral measurement system of claim 6, wherein the third non-focusing module comprises: a sixth lens for receiving the diffracted light outputted from the second grating; and a seventh lens And a track for changing the diffracted light outputted from the sixth lens to output the monochromatic light parallel to the normal of the system to the planar photodetector. A spectral measurement method is applicable to a spectral measurement system, wherein the spectral measurement system comprises a first non-focusing module, a second non-focusing module, a third non-focusing module, a first grating and a The second grating, the spectral measurement method includes: receiving, by the first non-focusing module, an incident light emitted by a test object, so that the incident light is parallel to a system normal; by using the first grating The second non-focusing module selects a specific wavelength from the incident light output by the first non-focusing module, so that the second non-focusing module outputs only one diffracted light having the specific wavelength; The second grating and the second non-focusing module cancel the optical path difference caused by the first grating; and receive the diffracted light outputted from the second grating by the third non-focusing module to output and The above system normal is parallel to one of the monochromatic lights. The method for measuring a spectrum according to claim 8, further comprising: adjusting the first grating such that an incident angle of the incident light and the first grating corresponds to the specific wavelength; and adjusting the second grating so that The angle and direction of rotation of the second grating are the same as the angle and direction of rotation of the first grating to compensate for the optical path difference caused by the first grating. The method for measuring a spectrum according to claim 9 further includes receiving the monochromatic light by a one-side photodetector to analyze an image of the object to be tested.