Miniature spectrophotometer

Abstract

The utility model provides a miniature beam splitting brightness meter, which comprises a diaphragm, a beam splitting grating, a lens assembly and a detector, the diaphragm is positioned at the front end of the beam splitting grating along the direction of incident light, the incident light reaches the beam splitting grating through the diaphragm, the incident light enters the lens assembly after the beam splitting grating splits the incident light, and the detector is used for detecting the incident light. And then the incident light reaches the detector through the lens assembly, and the detector obtains a spectral signal value of the incident light.

Description

Technical Field

[0001] The utility model relates to the technical field of measuring brightness, in particular to a micro-spectrometer. Background Art

[0002] The description herein merely provides background information related to the present invention and does not necessarily constitute prior art.

[0003] A luminance meter is a professional instrument for measuring brightness, i.e., a dosimeter for measuring light and color. It is a commonly used test instrument in the fields of lighting engineering, light sources and light-emitting devices, film and television, traffic signals, architecture, atmospheric photometry, etc. It is often used to measure the brightness of various indoor surfaces (such as countertops, floors, walls, ceilings, indoor facilities, etc.), as well as the brightness of outdoor roads. A luminance meter is one of the common instruments and equipment that every chemical analysis laboratory must have, and it has been widely used in various quantitative and qualitative analyses.

[0004] Brightness refers to the intensity of light that can enter the human eye and be felt, and illuminance refers to the amount of light received by the illuminated surface. Lv = d2Φv / dΩ·dΑ·cosθ. The luminance meter measures luminous bodies, and the unit is candela / square meter.

[0005] like Figure 1 It is a schematic diagram of a brightness meter in the prior art, wherein the brightness meter in the prior art uses a fixed-focus standard lens to collimate the light source to be measured through the field aperture, and then the light is sensed by the sensor through the filter to calculate the color coordinates, but the spectrum cannot be produced. The spectrophotometer that can generate a spectrum using a grating has a complex optical path and is extremely large in size. Utility Model Content

[0006] A major advantage of the present invention is that it provides a micro-spectrometer, wherein the micro-spectrometer uses grating spectrometry to achieve high-precision spectral output and has a large spectral range for measurement.

[0007] Another advantage of the present invention is that it provides a micro spectrophotometer, wherein the micro spectrophotometer does not require an external lens, which is beneficial to reducing the overall volume and having a compact structure.

[0008] According to one aspect of the utility model, a micro-spectrometer of the utility model that can achieve the aforementioned purpose and other purposes and advantages includes an aperture, a spectroscopic grating, a lens assembly and a detector, wherein the aperture is located at the front end of the spectroscopic grating along the direction of the incident light, and the incident light reaches the spectroscopic grating through the aperture. After the spectroscopic grating splits the incident light, the incident light enters the lens assembly and then reaches the detector through the lens assembly, and the detector obtains the spectral signal value of the incident light.

[0009] According to an embodiment of the present utility model, the lens assembly includes at least one lens and a lens diaphragm, wherein the lens diaphragm is arranged at the front end of the at least one lens along the direction of incident light.

[0010] According to an embodiment of the utility model, it further comprises an outer aperture, wherein the outer aperture is arranged at the front end of the aperture along the light incident direction.

[0011] According to an embodiment of the present invention, the diameter of the outer aperture is 1-10 mm.

[0012] According to an embodiment of the utility model, it further comprises a shell, wherein the shell has a containing space, and the aperture, the spectroscopic grating, the lens assembly and the detector are arranged in the containing space of the shell.

[0013] According to an embodiment of the utility model, the lens assembly and the detector are arranged at the bottom of the housing, wherein the spectroscopic grating is suspended on the top of the housing in an inclined manner, and an incident angle exists between the spectroscopic grating and the aperture.

[0014] According to an embodiment of the present invention, the aperture is implemented as an entrance slit, wherein the height of the slit is 0.1-0.5 mm.

[0015] According to an embodiment of the present invention, the spectroscopic grating is implemented as a blazed grating, wherein the number of lines N of the grating is 1200 lines.

[0016] According to an embodiment of the present invention, the detector is a CMOS chip or a CCD chip.

[0017] According to an embodiment of the present utility model, the lens assembly and the detector are assembled into a photosensitive module, wherein the photosensitive module is disposed in the housing of the brightness meter.

[0018] According to one embodiment of the present invention, the spectral bandwidth of the spectral grating is The slit height H of the diaphragm, the lens aperture D, and the distance L from the diaphragm to the lens diaphragm, where the divergence angle of the incident light beam Calculate the brightness value based on θ.

[0019] According to an embodiment of the present invention, the slit height H of the diaphragm is 0.3 mm; the lens aperture D is 0.8 mm; the horizontal distance between the slit and the beam splitter grating is 12 mm; the inclination angle is 10°

[0020] Through understanding of the following description and drawings, further objects and advantages of the present utility model will be fully reflected.

[0021] These and other objects, features and advantages of the present invention are fully reflected in the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The technical solution of the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. In the accompanying drawings, unless otherwise specified, the same reference numerals are used to represent the same components. Among them:

[0023] Figure 1 The present invention is a schematic diagram of the optical path of a brightness meter in the prior art.

[0024] Figure 2 It is a schematic diagram of the optical path of a micro-spectrometer according to the first preferred embodiment of the utility model.

[0025] Figure 3 It is a structural schematic diagram of the micro-spectrometer according to the first preferred embodiment of the utility model.

[0026] Figure 4 It is a schematic diagram of the micro-spectrometric brightness measurement according to the first preferred embodiment of the utility model. DETAILED DESCRIPTION

[0027] It should be pointed out that the embodiments shown in the drawings are only used as examples to specifically and vividly explain and illustrate the concept of the utility model. The size and structure thereof are not necessarily drawn in proportion, nor do they constitute a limitation to the concept of the utility model.

[0028] The directional terms such as up, down, left, right, front, back, front, back, top, bottom, etc. mentioned or may be mentioned in this specification are defined relative to the structures shown in the various drawings. They are relative concepts and may change accordingly according to different positions and different usage conditions. Therefore, these or other directional terms should not be interpreted as restrictive terms.

[0029] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0030] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0031] Referring to the drawings of this application specification Figures 2 to 4 As shown, a micro spectrophotometer according to the first preferred embodiment of the present application is explained in the following description. The micro spectrophotometer includes an aperture 10, a spectroscopic grating 20, a lens assembly 30 and a detector 40, wherein the aperture 10 is located at the front end of the spectroscopic grating 20 along the direction of the incident light, that is, the incident light reaches the spectroscopic grating 20 through the aperture 10, and after the spectroscopic grating 20 splits the incident light, the incident light enters the lens assembly 30, and then passes through the lens assembly 30 to reach the detector 40, and the detector 40 obtains the spectral signal value of the incident light.

[0032] The lens assembly 30 includes at least one lens 31 and a lens diaphragm 32, wherein the lens diaphragm 32 is arranged at the front end of the at least one lens 31 along the incident light direction, that is, the incident light reaches the at least one lens 31 after passing through the lens diaphragm 32. Preferably, the lens diaphragm 32 can be a built-in lens diaphragm.

[0033] The micro-spectrometer can further include an outer aperture 50, wherein the outer aperture 50 is arranged at the front end of the aperture 10 along the light incident direction, and is used to block stray light and prevent dust, wherein the incident light forms a nearly collimated light beam through the outer aperture 50, and the nearly collimated light beam then passes through the aperture 10 to reach the spectroscopic grating 20.

[0034] As an example, in a specific example of the present application, the outer aperture 50 is formed on a transparent substrate, wherein the transparent substrate is a glass sheet. The transparent substrate plays a protective role, for example, the aperture is attached to the transparent substrate, or is directly formed on the transparent substrate by a process such as silk screen printing, so as to limit stray light and dust from entering the interior of the brightness meter. Preferably, the diameter of the outer aperture 50 is 1-10 mm.

[0035] The micro-spectrometer further includes a housing 60, wherein the housing 60 has a storage space, and the aperture 10, the spectroscopic grating 20, the lens assembly 30 and the detector 40 are arranged in the storage space of the housing 60. The housing 60 is provided with an incident slit 601, which is formed on one side of the housing 60. The incident slit 601 corresponds to the spectroscopic grating 20. The incident light enters the storage space of the housing 60 from the incident slit 601 of the housing 60, that is, the incident slit 601 forms the aperture 10. It should be noted that in other embodiments, the aperture may also be arranged or formed between the incident slit 601 and the spectroscopic grating 20.

[0036] As an example, in a specific example of the application, the outer aperture 50 is disposed inside the housing 60, corresponding to the incident slit 601 of the housing 60. After passing through the outer aperture 50, the incident light enters the incident slit 601, the beam splitter grating 20, and then enters the lens assembly 30 to reach the detector 40.

[0037] Preferably, the housing 60 includes a base 61 and a cover 62 disposed on the base 61, wherein the cover 62 and the base 61 form a storage space for accommodating the spectroscopic grating 20, the lens assembly 30 and the detector 40, wherein the detector 40 is fixed to the base 61, and the lens assembly 30 is disposed along the light sensing path of the detector 40. The incident slit 601 is formed on one side of the cover 62, and the aperture 10 is formed by the incident slit 601.

[0038] The lens assembly 30 and the detector 40 are arranged at the bottom of the shell 60, wherein the spectroscopic grating 20 is suspended on the top of the shell 60 in an inclined manner, wherein there is an incident angle between the spectroscopic grating 20 and the nearly collimated light beam formed by the aperture 10, and after the incident light is incident from the aperture 10 to the spectroscopic grating 20, the spectroscopic grating 20 splits the incident light and reflects it to the optical component 30.

[0039] It is worth mentioning that in this preferred embodiment of the present application, the aperture 10 is implemented as an incident slit with a width W and a height H or a circular hole diameter A. Preferably, the aperture 10 is implemented as an incident slit, wherein the height of the slit is 0.1-0.5 mm. The spectral bandwidth of the light splitting grating 20 is A small incident angle is required to achieve a small spectral width; in the preferred embodiment of the present application, the aperture 10 does not need to be provided with any lens, so the aperture of the incident light path, such as the slit height H of the aperture 10 and the lens aperture D and the distance L from the aperture to the lens aperture, does not consider the diffraction effect because the size of each aperture is much larger than the wavelength; the divergence angle θ of the incident light beam is determined by the spatial geometric relationship of the three; According to the brightness meter system parameters, θ is also the horizontal solid angle of the brightness meter; the brightness value can be calculated based on this.

[0040] The spectroscopic grating 20 is implemented as a blazed grating, wherein the number of lines N of the grating is 1200 lines, which can realize spectrum detection in the range of 350-1050 nm.

[0041] Preferably, in a specific example of the present application, the lens assembly 30 is located on the photosensitive path of the detector. Preferably, the optical axis center line of the lens assembly 30 is substantially parallel to the photosensitive path of the detector. After the incident light passes through the aperture 10 and enters the spectroscopic grating 20 to be split, it enters the lens assembly 30 and reaches the detector 40 to obtain the spectral signal value. It should be noted that the detector 40 can be implemented as a CMOS chip, a CCD chip, etc. It is worth mentioning that, in a specific example of the present application, the lens assembly 30 and the detector 40 can be assembled into a photosensitive module, wherein the photosensitive module is arranged in the housing 60 of the brightness meter.

[0042] The micro-spectral brightness value is calculated as the illumination of the detector 40 divided by the solid angle of the incident light; the illumination of the detector 40 can be calculated by the detector sensitivity value and the lens parameters; the solid angle can be calculated by the plane angle according to Ω=2π(1-cos(θ / 2)).

[0043] The spectroscopic grating 20 is tilted relative to the lens assembly 30 and the diaphragm 10, wherein the actual divergence angle is determined by the optical path composed of the virtual aperture of the diaphragm 10 and the lens aperture of the lens assembly 30 (determined by the lens diaphragm 32) in the horizontal direction, and the actual aperture diameter of the lens is D; in the present application, the spectroscopic grating 20 is tilted in the housing 60, and its tilt angle B is 5-15°; then the size of the aperture D1 in the horizontal direction is D1=D×tan(B), and since the angle B is small, the size of D1 is compressed, so the divergence angle will also be reduced.

[0044] In addition, the spectral bandwidth Therefore, the horizontally compressed divergence angle can reduce the spectral bandwidth and improve the spectral resolution accuracy. Therefore, by optimizing the various optical path parameters, it is possible to meet the solid angle condition of the human eye observer of the brightness meter and achieve high spectral accuracy; while the existing brightness meter applications generally have to meet the human eye observer condition of 2°, and there will also be conditions for smaller angle observers, which are used to measure smaller luminous objects. As an example, in a specific example of the present application, the slit height H of the aperture 10 is 0.3mm; the lens aperture D is 0.8mm, and the horizontal distance between the slit and the dichroic grating 20 is 12mm; the inclination angle is 10°; then according to the above calculation, D1=0.14mm, θ=2°; the brightness meter human eye observer condition is met.

[0045] Furthermore, the aperture of the diaphragm 10 and the lens can be reduced, or the distance between the beam splitter grating 20 and the slit of the diaphragm 10 can be increased to reduce the detection solid angle to meet the conditions of a smaller angle observer and to measure a smaller luminous object; for example, a diameter of 0.2 mm; at this time, the detection angle is 1.1°. The illuminance values ​​received under different inner diaphragm diameters are different, so different calibration coefficients need to be called inside the luminance meter to calculate the brightness value.

[0046] The present application further provides a variant embodiment of the above-mentioned first preferred embodiment, which is different from the above-mentioned first preferred embodiment in that an external aperture is not provided in this variant embodiment, and the micro-spectrometer includes a transparent substrate, wherein the transparent substrate is provided at the front end of the aperture 10 in the light incident direction, which serves to block dust.

[0047] It should be understood by those skilled in the art that the embodiments of the present invention described above and shown in the accompanying drawings are only examples and do not limit the present invention. The purpose of the present invention has been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments, and the embodiments of the present invention may be deformed or modified in any way without departing from the principles.

[0048] The technical scope of the present invention is not limited to the contents in the above description. Those skilled in the art can make various deformations and modifications to the above embodiments without departing from the technical concept of the present invention, and these deformations and modifications all belong to the protection scope of the present invention.

Claims

1. A micro-spectrometer, characterized in that: The invention comprises an aperture, a spectroscopic grating, a lens assembly and a detector, wherein the aperture is located at the front end of the spectroscopic grating along the direction of the incident light, the incident light reaches the spectroscopic grating through the aperture, after the spectroscopic grating splits the incident light, the incident light enters the lens assembly, and then reaches the detector through the lens assembly, and the detector obtains the spectral signal value of the incident light.

2. The micro-spectrometer according to claim 1, wherein the lens assembly comprises at least one lens and a lens aperture, wherein the lens aperture is arranged at the front end of the at least one lens along the direction of the incident light.

3. The micro-spectrophotometer according to claim 2, further comprising an outer aperture, wherein the outer aperture is arranged at a front end of the aperture along a light incident direction.

4. The micro-spectrometer according to claim 3, wherein the diameter of the outer aperture is 1-10 mm.

5. The micro-spectrophotometer according to claim 2 further comprises a housing, wherein the housing has a receiving space, and the aperture, the spectroscopic grating, the lens assembly and the detector are arranged in the receiving space of the housing.

6. The micro-spectrometer according to claim 5, wherein the lens assembly and the detector are arranged at the bottom of the housing, wherein the spectroscopic grating is suspended on the top of the housing in an inclined manner, and wherein an incident angle exists between the spectroscopic grating and the aperture.

7. The micro-spectrometer according to claim 1, wherein the aperture is implemented as an entrance slit, wherein the height of the slit is 0.1-0.5 mm.

8. The micro-spectrometer according to claim 1, wherein the spectroscopic grating is implemented as a blazed grating, wherein the number of lines N of the grating is 1200 lines.

9. The micro-spectrophotometer according to claim 6, wherein the lens assembly and the detector are assembled into a photosensitive module, wherein the photosensitive module is disposed in the housing of the photometer.

10. The micro-spectrometer according to claim 1, wherein the spectral bandwidth of the light splitting grating is The slit height H of the diaphragm, the lens aperture D, and the distance L from the diaphragm to the lens diaphragm, where the divergence angle of the incident light beam Calculate the brightness value based on θ.

11. The micro-spectrometer according to claim 7, wherein the slit height H of the diaphragm is 0.3 mm; the lens aperture D is 0.8 mm, the horizontal distance between the slit and the spectroscopic grating is 12 mm, and the inclination angle is 10°.

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