The utility model content
The technical problems to be solved in the utility model provides a kind of grating spectrophotometer, overcome difficult realization of grating spectrophotometer catoptron adjustment that prior art is applied to Biochemical Analyzer, and the defective that wastes time and energy, and because of using catoptron spectrophotometer physical dimension to increase, be unfavorable for the defective that the device one-piece construction is installed, and, influence the defective of signal to noise ratio (S/N ratio), and because of using catoptron to increase the defective of Material Cost because of using catoptron to cause signal intensity to reduce.
The utility model is to solve the problems of the technologies described above the technical scheme that is adopted to be:
A kind of grating spectrophotometer, comprise the light source that sets gradually along the direction of propagation of light, front lens, reaction cup, rear lens, entrance slit, flat filed concave grating and detector array, the center of described light source, described front lens, described reaction cup, described rear lens, the optical axis of described entrance slit and described flat filed concave grating is located along the same line, described front lens, described reaction cup, described rear lens, described entrance slit, the position relation of described flat filed concave grating and described detector array guarantees that the light beam that described light source sends focuses on through described front lens, described reaction cup transmission, described rear lens focuses on, described entrance slit transmission, described flat filed concave grating reflection arrives described detector array at last and lists.
Described grating spectrophotometer, wherein said light source is made as halogen tungsten lamp.
The further optimization of described grating spectrophotometer is: described front lens comprises two plano-convex structure lens that physical dimension is identical.
The further optimization of described grating spectrophotometer is: the convex surface of described two plano-convex structure lens is oppositely arranged.
The further optimization of described grating spectrophotometer is: described rear lens is made as the biconvex lens that the convex curvature radius equates.
The further optimization of described grating spectrophotometer is: the convex curvature radius of described biconvex lens equals the convex curvature radius of described plano-convex structure lens.
The further optimization of described grating spectrophotometer is: described detector array is made as the photodiode detector array.
Described grating spectrophotometer wherein also comprises being used for analog-to-digital AD plate, and described AD plate is pegged graft with described detector array and linked to each other.
The further optimization of described grating spectrophotometer is: described AD plate places independently in the installation room.
The further optimization of described grating spectrophotometer is: described photodiode detector array is made as the unequal discrete type photodiode detector of photodiode spacing array.
The beneficial effects of the utility model: the utility model grating spectrophotometer does not use catoptron, has therefore eliminated the serial defective because of using catoptron to cause; And structurally still have the innovation part: directly peg graft between AD plate and the detector panel, the installation site of AD plate and the installation site of other optical device isolate, place independently in the installation room, so both convenient adjustment to AD plate enlargement ratio has reduced the interference to optical system again; The utility model grating spectrophotometer uses photodiode spacing unequal discrete type photodiode detector array and does not use the equal integrating optical electric diode detector array of photodiode spacing, the problem that detector array can not satisfy the design needs so just can not occur; The utility model grating spectrophotometer compact conformation, Installation and Debugging are convenient, and are stable and be beneficial to production in enormous quantities.
Embodiment
With embodiment the utility model is described in further detail with reference to the accompanying drawings below:
As Fig. 1, Fig. 2 and shown in Figure 3, the utility model grating spectrophotometer comprises light source 1, front lens 2, reaction cup 3, rear lens 4, entrance slit 5, flat filed concave grating 6, detector array 7, the AD plate 8 that sets gradually along the direction of propagation of light.The optical axis of the center of light source 1, front lens 2, reaction cup 3, rear lens 4, entrance slit 5, flat filed concave grating 6 is located along the same line, the position relation of light source 1, front lens 2, reaction cup 3, rear lens 4, entrance slit 5, flat filed concave grating 6, detector array 7 guarantees that the light beam that light source 1 sends reflects through front lens 2 focusing, reaction cup 3 transmissions, rear lens 4 focusing, entrance slit 5 transmissions, flat filed concave grating 6, arrives on the detector array 7 at last.
Detector array 7 presss from both sides an angle [alpha] with optical axis, the angle at α angle is unique definite by flat filed concave grating 6, and detector 7 also is uniquely to be determined by flat filed concave grating 6 apart from the distance L of flat filed concave grating 6 centers (intersection point of optical axis and concave spherical surface), use different flat filed concave gratings 6 in general a, L value be different, must place detector array 7 in strict accordance with flat filed concave grating 6 initial design values.And the position of each wavelength is also well-determined by flat filed concave grating 6 on the detector array 7.
Principle of work: light source 1 sends white light (polychromatic light) and is focused on reaction cup 3 centers by front lens 2, will carry information such as solution concentration in the reaction cup 3 by the light after the reaction cup 3.Focusing on entrance slit place 5 again through rear lens 4, to project on the flat filed concave grating 6 by the light behind the entrance slit 5, through grating beam splitting, detect the light intensity of each road wavelength at place, detector array 7 places, individual slit array is wherein arranged before detector array 7, its function is exactly to select to see through each the road wavelength that needs, and unwanted wavelength is then blocked by it.Detector array 7 detects each road photosignal (simulating signal) and passes to AD plate 8, and AD plate 8 is passed to main control unit with digital signal after finishing analog to digital conversion.
The picture of the filament of halogen tungsten lamp becomes in the reaction cup center in specific embodiment of the utility model, and reduce particularly spherical aberration of aberration as far as possible, obtain a meticulous sharp keen picture point of filament in the reaction cup center, picture point will reach tries one's best little and concentrates as far as possible, like this, the energy that enters in the reaction cup can be as much as possible, solution minimal reaction volume is just little in the more little reaction cup that then needs of picture point simultaneously, and the minimal reaction volume is a vital index for Biochemical Analyzer, can save consumptive materials such as reagent in a large number.Used the front lens group of plano-convex structure especially, and that plano-convex structure lens have is simple in structure for this reason, the processing aspect, advantage such as aberration correction is good, two plano-convex structure lens are identical in specific embodiment of the utility model.As shown in Figure 2,1 and 1 ' satisfies Gauss formula, that is:
Just can calculate the concrete data of imaging by Gauss formula.
Rear lens is imaged on the entrance slit place with the luminous point in the reaction cup, because the slit array opening size is the flat filed concave grating decision, its inlet size is very little, in any case the light that this slit sees through also just is imaged on the part sampling of light herein.Therefore in order to simplify, rear lens adopts the single element lens structure can satisfy the demand, in order to save processing charges, the biconvex lens that rear lens uses two convex curvature radiuses to equate, and this radius-of-curvature peace male structure front lens convex curvature radius is identical, so only need a processing model just can finish the processing of front lens and rear lens, price easy to process is cheap certainly.This imaging relations also satisfies Gauss formula, can calculate the concrete data of imaging equally.
When flat filed concave grating has determined that the distance, detector array of size, slit array and the flat filed concave grating of slit array are installed with the folded angle of optical axis and and the distance of detector array face and flat filed concave grating, so then these above-mentioned sizes and angle have just been determined by unique to select different flat filed concave gratings.
Different wave length on the photodiode detector array in the corresponding wavelength selected scheme, select for use different detector array pixels to survey photosignal, and each road photosignal (simulating signal) delivered in the AD plate 8, after the number conversion of AD template die, digital signal is uploaded to main control unit, and then the repertoire of grating beam splitting photometric module is finished.
Halogen tungsten lamp, front lens group, saturating ultraviolet organic glass reaction cup, rear lens, entrance slit and flat filed concave grating optical axis are coaxial.The physical construction that accompanying drawing 2 shows realizes light shaft coaxle.
And halogen tungsten lamp is 20W, and two lens are identical in the front lens group, and one of radius-of-curvature is that one on plane is 20.137mm, and thickness is 5.97mm, and material is K9, and two center of lens distance of centre of gravitys are 10.05mm.Light source is 43mm apart from the distance of front lens group, and front lens group is 27.5mm apart from reaction cup.The two sides radius-of-curvature of rear lens is 20.137mm, centre distance 5mm, and it is 32mm, 28mm apart from reaction cup and entrance slit respectively.Concave grating center, entrance slit anomaly field is 98.2mm, and flat filed concave grating is classified 98.2mm as apart from detector array.Detector array face and optical axis folder 70 degree angles.The spectral distribution that flat filed concave grating produces is fixed, and then corresponding wavelength must be placed on ad-hoc location with detector.
Front lens group, rear lens all adopts K9 glass to make, entrance slit width is 0.5mm, highly be 5mm, the photodiode detector array adopts 35 pixels, spectrum face width degree 34.9mm, light intensity that can detected 12 wavelength, corresponding wavelength is 340nm, 375nm, 405nm, 455nm, 505nm, 540nm, 572nm, 605nm, 670nm, 700nm, 748nm, 794nm.
As shown in Figure 4 and Figure 5, the integrated form photodiode array 72 of prior art has the advantages that photodiode 721 spacings equate, select to have bigger restriction for spectrophotometric modular design medium wavelength, make and select wavelength freedom fully, be subjected to the restriction of 721 sizes of photodiode.The utility model embodiment adopts the unequal discrete type photodiode detector of photodiode 711 spacings array 71, does not then have this problem fully, can place each photodiode 711 according to fixed wave length scheme.Adopt discrete type photodiode detector array 71 can also save cost greatly, customization discrete type photodiode detector array 71 can be by making a circuit board that satisfies dimensional requirement, each photodiode 711 is just passable, very convenient on the paster then, and low price.Adopt discrete type photodiode detector array 71 to also have a very big benefit, slit array and color filter directly can be attached on the discrete type photodiode detector array 71 of customization, simple and convenient precision height is beneficial to production in enormous quantities.If adopt integrating optical electric diode detector array 72, paste thereon that slit array and color filter not only bother but also precision also is not easy to guarantee that operating difficulties is wasted time and energy very much.
In order to improve Signal-to-Noise, reduce decay and interference in the signals transmission, be directly to peg graft between AD plate behind the detector and the detector panel, and circuit board is completely shielded in inside, disturb also little.Because and other optical device is in the space, two Room separately, do not disturb mutually, the AD plate needs often to adjust enlargement ratio, and this design can not cause opens the primary optical system chamber and interference optical system can be opened AD plate chamber again and carry out the adjustment of enlargement ratio.
The utility model grating spectrophotometer satisfies following performance requirement:
Measure wavelength coverage: 340~850nm;
Wavelength accuracy: ± 2nm;
Half-wave wide (FWHM): 6nm+2nm;
Detect number of wavelengths: 12;
Linear measurement range: 0~3.0 (linear error ± 5%);
Absorbance accuracy (as shown in table 1):
Table 1
Absorbance |
Permissible error |
0.5 |
±0.02 |
1 |
±0.04 |
Absorbance stability: to absorbance is 0.2 solution METHOD FOR CONTINUOUS DETERMINATION 1 hour, and the difference of maximal value and minimum value is not more than 0.01;
Absorbance repeatability: to absorbance is 1.0 solution duplicate measurements 20 times, and CV represents with the coefficient of variation, is not more than 1%;
Absorbance resolution: 0.001A;
The minimal reaction volume that detects: 150ul.
Those skilled in the art do not break away from essence of the present utility model and spirit, can there be the various deformation scheme to realize the utility model, the above only is the preferable feasible embodiment of the utility model, be not so limit to interest field of the present utility model, the equivalent structure that all utilization the utility model instructionss and accompanying drawing content are done changes, and all is contained within the interest field of the present utility model.