CN102767766A

CN102767766A - Arrayed LED area light source

Info

Publication number: CN102767766A
Application number: CN2012102709193A
Authority: CN
Inventors: 杨红; 冯旭东; 刘宏权
Original assignee: CHANGCHUN MEITAI TECHNOLOGY Co Ltd
Current assignee: CHANGCHUN MEITAI TECHNOLOGY Co Ltd
Priority date: 2012-08-01
Filing date: 2012-08-01
Publication date: 2012-11-07

Abstract

An arrayed LED area light source belongs to the field of optical detection and is capable of vertically illuminating sample solution. Arrayed LEDs are mounted on one surface of a circuit board, a circular hole is reserved at the center of the circuit board, a concave reflector is mounted on one surface, mounted with the LEDs, of the circuit board, a front convex lens is arranged on the other surface of the circuit board, a sample reservoir is arranged between the front convex lens and a rear convex lens, a light-splitting optical system is arranged behind the rear convex lens, and a slot is reserved on the light-splitting optical system. By above technical scheme, the arrayed LED area light source has the advantages that a plurality of LEDs are utilized as light sources to combine the arrayed LED area light source; is uniform in luminous intensity, good in heat stability and long in service life; and improves detection accuracy of the sample solution when being matched with a double focusing optical system. The arrayed LED area light source can be widely used to a detecting instrument of a light-splitting system.

Description

The array-type LED area source

Technical field

The invention belongs to the optical detection field.

Background technology

Adopt technology that AAS carries out sample detection suitable maturation and being widely used.Wherein LED is quite general as light source for instrument.And a plurality of led array also appear in this type of detecting instrument as same light source for instrument.Yet people have also found the some shortcomings part of led array light source in long-term practice.When adopting led array combinatorial surface light source direct irradiation sample cell, not necessarily vertical irradiation is on the entrance slit of beam splitting system for the light that each LED sends, and most of light source gets into slit with the form that the vertical line with entrance slit is certain angle.

As shown in Figure 4, solid line is the light that sends from LED, the approach sample solution gets into entrance slit among the figure.Make this light to depart from the entering solution of solution plane of incidence normal

; Refraction angle in solution is

; Because two transparent surfaces of solution are parallel to each other, then light also is

in the angle of emergence of solution opposite side.Make slit to the distance of sample solution light exit plane is

; The thickness of sample solution is

; LED is

to the distance of sample solution light plane of incidence, and LED is

to the vertical range of slit.For a fixing light path system,

,

, ,

four distances are constant.Make LED to the distance of incident normal is

; The distance of two normals is

; The outgoing normal is

to the distance of slit, then has Ru Xia Guan Xi between

,

,

and

,

:

(1)

(2)

(3)

(4)

Formula 1,2,3 substitution formulas 4 can be solved through abbreviation:

(5)

Make sample solution with respect to the refractive index of air is

, then

is the real number greater than 1.Get by the geometric optics law of refraction:

(6)

Because

and

is the acute angle between the 0-

, so can be tried to achieve by formula 6

(7)

Formula 7 substitution formulas 5 are got:

(8)

Because , ,

,

are known constant, so squint angle

is to be a monotonic increase curve of independent variable with sample solution refractive index

.When 1 increased to

, the value of squint angle

increased to

from

as

.Can be got by above analysis, under the situation of the non-perpendicular irradiation of light, the angle that the sample solution change of refractive can cause getting into the LED light off-axis of slit changes, thereby causes the variation of incident intensity, can cause measure error.Analysis by the front can get equally; As when being 0;

perseverance is zero, can not cause this error when promptly the light vertical irradiation is to sample solution.In view of this, make light source vertical irradiation sample solution just can reduce to detect error.

Summary of the invention

The purpose of this invention is to provide a kind of array-type LED area source that can make light source vertical irradiation sample solution.

The present invention is equipped with array-type LED in the one side of circuit board; The circuit board center is the circuit board circular hole; At circuit board LED being installed simultaneously there is concave mirror, and the another side of circuit board has preceding convex lens, is sample cell between preceding convex lens and the back convex lens; Back convex lens are beam-splitting optical system at the back, and slit is arranged on the beam-splitting optical system.

The technique scheme that adopts of the present invention, its distinguishing feature is:

1, adopts a plurality of LED as light source, can be combined into the array-type LED area source.

2, array-type LED area source, luminous intensity evenly, Heat stability is good, long service life.

3, the array-type LED area source cooperates the double focusing optical system, has improved the accuracy of detection of sample solution.

The present invention can be widely used in the detecting instrument of beam splitting system.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a channel plate array LED structural representation of the present invention;

Fig. 3 is a circuit theory sketch map of the present invention; LED among the figure

Fig. 4 is prior art light source schematic diagram when passing sample solution.

The specific embodiment

[0009] the present invention is equipped with array-type LED 2 in the one side of circuit board 3; Circuit board 3 centers are circuit board circular holes 9; At circuit board 3 LED2 being installed simultaneously there is concave mirror 1, and the another side of circuit board 3 has preceding convex lens 4, is sample cell 5 between preceding convex lens 4 and the back convex lens 6; Back convex lens 6 back are beam-splitting optical systems 8, and slit 7 is arranged on the beam-splitting optical system 8.

Below in conjunction with accompanying drawing the present invention is carried out detailed description:

The present invention includes parabolic concave mirror, channel plate array LED, preceding convex lens, sample cell, back convex lens.

Adopt a plurality of LED to be combined into the array-type LED area source.

The array-type LED area source cooperates the double focusing optical system, makes the area source of beginning pool spot light at last, has improved the accuracy of detection of sample solution.

Of the present inventionly mainly provide a kind of array-type LED surface light source system that can make light source vertical irradiation sample solution.Array-type LED area source of the present invention adopts parabolic concave mirror, channel plate array LED, preceding convex lens, sample cell, back convex lens.Wherein, the illumination that channel plate array LED sends is mapped on the parabolic concave mirror, and convex lens before arriving through light path reflection back are penetrated by preceding convex lens with the directional light mode then.The directional light of this moment can pass the solution in the sample cell with vertical sample cell mode, arrives the back convex lens then.The emergent light of back convex lens focuses on a bit, and focus can be used as spot light.Generally be positioned at the slit place of beam-splitting optical system.Said parabolic concave mirror is the deielectric-coating concave mirror, reflection wavelength 400-750nm, average reflectance>99%, can be with focusing on a bit after the reflection of LED incident light.Said channel plate array LED is that a plurality of LED vertically evenly are welded on formation array LED area source on the circular circuit board, and the light intensity of each LED is regulated by the potentiometer on the circuit board, and the light intensity of LED is consistent.Circular circuit board center is that a circular hole can let reverberation pass through.Convex lens are processed by optical glass with the back convex lens before said, and the size of preceding convex lens is less than the size of back convex lens, and the big focal length length of the size of back convex lens helps the slit place that focus behind the optically focused falls within beam-splitting optical system.Said sample cell is general quartz glass material, and size requires to match with instrument detecting, does not do special restriction at this.

It is 20mm parabolic concave mirror 1 that array-type LED area source of the present invention has focal length, can be with focusing on the focus of parabolic concave mirror 1 after the reflection of LED incident light.3 is channel plate array LED diameter 40mm; It is the circular hole of 15mm that there is a diameter centre; 2 is the LED of 40 diameter 3mm different wave lengths, vertically evenly is welded on to form the array LED area source on the circular circuit board, and the circular hole center of circle of circuit board is dropped on the primary optical axis of parabolic concave mirror.Circuit board plane is 10mm to the distance of parabolic concave mirror fixed point; Therefore the axial ray of 40 LED penetrates directional lights from convex lens 4 through converging on the focus after the mirroring of parabolic concave reflection and being positioned at simultaneously on the focus of preceding convex lens 4 one sides that focal length is 3mm.And on the sample solution surface of vertical irradiation in sample cell 5.Back convex lens 6 focal lengths are 20mm, and directional light focuses on a bit after convex lens 6 outgoing of back, and focus falls within slit 7 places of beam-splitting optical system 8 as spot light.So device all is positioned on the primary optical axis of parabolic concave mirror.

As shown in Figure 2, it is array LED that channel plate array LED contains a circuit board 3,2, vertically evenly is welded on to form the array LED area source on the circular circuit board, and 9 is the circular hole of circuit board, and reverberation is passed through.

Operation principle of the present invention: when the array-type LED area source is started working; Array LED 2 emergent lights shine on the parabolic concave mirror 1; Convex lens 4 before shining after reverberation converges; After arriving back convex lens 6 behind the sample solution surface of directional light vertical irradiation in sample cell 5 of preceding convex lens 4, emergent light focuses on a bit, and focus falls within slit 7 places of beam-splitting optical system as spot light.In the present embodiment, adopt 3 super bright light emitting diodes, luminance parameter is more than 1000mcd.Brightness can be regulated through potentiometer.Circuit of the present invention connects can be with reference to figure 3, and this circuit is merely a kind of physical circuit connected mode that realizes aforementioned functional, not as the restriction that other possible circuit are connected.

The present invention is as light source for instrument, just can use after at first should correctly assembling adjustment on request.In use, should the focus of back convex lens 6 be got final product as slit 7 places that spot light falls within optical system.Brightness can be regulated through potentiometer.

Claims

1. array-type LED area source; It is characterized in that: the one side at circuit board (3) is equipped with array-type LED (2); Circuit board (3) center is circuit board circular hole (9); At circuit board (3) LED (2) one side being installed there is concave mirror (1), and the another side of circuit board (3) has preceding convex lens (4), is sample cell (5) between preceding convex lens (4) and the back convex lens (6); Back convex lens (6) back is beam-splitting optical system (8), and slit (7) is arranged on the beam-splitting optical system (8).