JP2000171299A - Light source for optical analysis - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide good wavelength purity with a compact light source having high utility. SOLUTION: LEDs I(light emitting diodes) 24a to 24e are disposed as light sources at a plurality of dispersive wavelength positions on a straight line 22 becoming wavelength dispersing positions when a spectroscope is constituted of a diffraction grating 20, switched at powers from a power source 26 by a changeover switch 28, and the powers are sequentially supplied to the LEDs 24a to 24e. Emitting slits 30 are disposed at positions of an inlet slit in the case of constituting the spectroscope by using the grating 20, and lights from the LEDs 24a to 24d sequentially switched and generated are dispersed at the grating 20, condensed at the position of the slit 30 and output.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device for supplying measurement light used in a photometric unit of an analyzer, and more particularly to a light source device for supplying light of a plurality of wavelengths whose spectral peaks are clearly separated. . Such a light source device is a clinical test field called dry chemistry using a test paper in which a filter paper is impregnated with a reagent or a plastic film coated with a reagent layer (hereinafter, these are collectively referred to as a reagent pad). It is suitable for use in measuring devices in various fields such as a spectroscopic analysis field for measuring absorbance and a measurement field for irradiating a living body with light and measuring the concentration of components in the living body using output light from the living body.

[0002]

2. Description of the Related Art In order to measure ammonia, BUN (blood urea nitrogen) or glucose, etc. in blood, blood is dropped on a reagent pad, and the color density and change in color detected by a detection layer of the reagent pad are measured. Measuring devices for clinical tests have been used which determine their concentration in blood by measuring by reflectance.

[0003] As shown schematically in FIG. 1, such a measuring apparatus is configured such that a sample is placed on each channel of a photometric unit 2 having a plurality of channels assigned to each measuring item, and on a reagent pad for each measuring item. The measurement is performed by arranging ones that have been dropped and colored. Each reagent pad incorporates a reagent that exhibits a unique color spectrum by reacting with a specific component in the sample, and is colored by dropping the sample.
The light emitted from the light source lamp 4 passes through the optical filter 6 to be converted into monochromatic light having a certain wavelength.
Are evenly distributed. As the optical filter 6, a filter rotor having a plurality of types (for example, five types) of filters having different transmission wavelengths and mechanically switching a filter mounted on an optical path is used.

As shown in FIG. 2, one channel of the photometric unit 2 is such that each of the optical fibers 8 is guided to a reagent pad 10 of each channel, and light of a certain wavelength distributed to each channel is supplied to the reagent pad. Irradiated at 10. In each of the reagent pads 10, the reflectance determined by the dye in the reagent that has reacted with the specific component in the sample is reflected by two photodiodes 12a and 12b arranged diagonally above (45 ° direction) the reagent pad 10. Detected as intensity.
Part of the light split by the optical fiber 8 is also guided to the photodiode 5 of the light quantity monitor, and the reflectance is based on the detection signals of the photodiodes 12a and 12b and the detection signal of the light quantity monitoring photodiode 5 in each channel. Is calculated.

[0005]

Since a plurality of monochromatic lights of a plurality of wavelengths are switched and extracted from the light source lamp 4 by the filter rotor, the size of the mechanism of the filter section 6 becomes large, and the size of the entire apparatus becomes large. But not
It also increases costs. An interference filter designed to transmit a specific wavelength range is used as the filter, but the selected monochromatic light has a wide wavelength range and cannot be said to have excellent wavelength purity. When the wavelength purity of the light irradiated to the colored reagent pad is low, the measurement accuracy of the reflectance determined by the coloration of the reagent pad to determine the component concentration in the sample leads to a decrease in the quantification accuracy. Accordingly, it is an object of the present invention to provide a light source device which is compact, has high practicality, and can increase the wavelength purity of light irradiated on a sample.

[0006]

SUMMARY OF THE INVENTION The present invention provides an optical system having a diffraction grating as a dispersive element, and a plurality of wavelength dispersion positions at each of a plurality of wavelength dispersion positions assuming that the optical system constitutes a spectroscope. Arrange a light source that contains the dispersion wavelength component at the position,
The spectroscope is a light source device in which an exit slit is disposed at a position where an entrance slit is disposed, and light emitted from the exit slit is supplied to a photometric unit of an analyzer. Since a diffraction grating is used to select a wavelength, a mechanical drive part can be eliminated, and the device can be reduced in size and weight, and the cost can be reduced. Since the diffraction grating is used as the dispersion element, the wavelength purity is improved as compared with the case where light is separated by a filter.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A plurality of light sources arranged include at least one of a halogen lamp, a hollow cathode lamp, an LED (light emitting diode) and an LD (laser diode). The diffraction grating may be a concave diffraction grating or a plane diffraction grating. The light emitted from the emission slit includes a plurality of wavelength lights having peak waveforms in which the peaks of the spectrum are separated from each other. However, this also includes the case where the wavelength regions at the tails of the peaks overlap each other between adjacent wavelength lights. In an analyzer such as that shown in FIG. 1, these multiple wavelength lights are used at different times. Therefore, in order to emit a plurality of wavelengths of light from the emission slit at different times without using a mechanical driving portion, it is preferable to sequentially switch and light the light sources.

[0008]

FIG. 3 schematically shows an embodiment. Reference numeral 20 denotes a concave diffraction grating, and LEDs 24a to 24e each including a dispersion wavelength component at each position as a light source are arranged at a plurality of positions on a wavelength dispersion position 22 when a spectroscope is configured using the diffraction grating. ing. The dispersion wavelength position becomes a longer wavelength from the LEDs 24a to 24e. The power from the power supply device 26 is switched to the LEDs 24a to 24e by the changeover switch 28, and the LEDs 24a to 24e are sequentially turned on.
24a to 24e. The exit slit 30 is arranged at the position of the entrance slit when the spectroscope is configured using the diffraction grating 20.

The light generated from the LEDs 24a to 24e is
Light having a wavelength corresponding to each position of the LEDs 24 a to 24 e is condensed at the position of the exit slit 30 by being dispersed by the diffraction grating 20. Since the LEDs 24a to 24e are sequentially switched and lit by the changeover switch 28, light having a wavelength corresponding to the position of each of the LEDs 24a to 24e is sequentially switched and extracted from the emission slit 30.

The characteristics of the diffraction grating 20 are as follows.
mm, inverse dispersion value is 15.5 nm / mm, radius of curvature is 58
mm. LEDs 24a to 24 arranged as light sources
The emission spectrum characteristics of e are shown in FIGS. The spectrum of the LED 24a is shown in FIG. 4, and is a broad spectrum having a peak wavelength at 430 to 440 nm. LEDs 24b, 24c and 24
d is of the same kind, and its spectrum is shown in FIG. 5 and is a broad spectrum having peak wavelengths near 460 nm and 580 nm, respectively. LED24
The spectrum of e is shown in FIG. 6 and is a broad spectrum having a peak wavelength at 850 nm.

FIG. 7 shows the spectral characteristics of light emitted from the exit slit 30 when the exit slit 30 has a slit width of 0.9 mm. LED 24a-2
Wavelength 405n determined by the place where 4e is arranged
m, 550 nm, 575 nm, 610 nm and 820 n
The full width at half maximum with each central wavelength being 14 to 17 nm
5 wavelengths of light having a narrow band peak are obtained.

If the slit width of the exit slit 30 is reduced to 0.5 mm, as shown in FIG. 8, the center wavelength is the same as that of FIG. 7, and the half width of the band is narrowed to increase the wavelength purity. A light source device that emits light of various wavelengths can be provided. However, the light amount decreases as the slit width of the exit slit 30 is reduced to increase the wavelength purity.

This light source device can be used, for example, as a light source device of the measuring device shown in FIG. Exit slit 3
0 is split by the optical fiber 8 and the photometric unit 2
Of the reagent pad of each channel and the light amount monitoring photodiode 5, and the switching is performed so that the five wavelength lights from the emission slit 30 are sequentially emitted, thereby sequentially measuring the reflectance of the reagent pad with the five wavelength lights. can do.

FIG. 9 shows another embodiment in which the present invention is applied to an optical system using a plane diffraction grating. LEDs 24a to 24f each including a dispersion wavelength component at each position as a light source at a plurality of dispersion wavelength positions on a wavelength dispersion position 22 when a spectroscope is configured using the plane diffraction grating 20a and the two concave mirrors 31 and 32. Is arranged. The dispersion wavelength position becomes a longer wavelength from the LEDs 24a to 24f. Although illustration is omitted, as in FIG.
The power from the power supply device 26 is switched by the changeover switch 28 to the LEDs 24a to 24f, and the LEDs 24a to 24f are sequentially turned on.
a to 24f. Diffraction grating 2
In the case where the spectroscope is constituted by using the first mirror 0a and the concave mirrors 31 and 32, the exit slit 30 is located at the position of the entrance slit.
Is arranged. Reference numeral 34 denotes a plane mirror that bends the direction of light so that the emitted light goes from the concave mirror 32 to the emission slit 30.

The light generated from the LEDs 24a to 24f is
Light having a wavelength corresponding to the position of each of the LEDs 24a to 24f is condensed at the position of the exit slit 30 by the diffraction grating 20a. Since the LEDs 24a to 24f are sequentially switched and turned on by the changeover switch, light having a wavelength corresponding to each position of the LEDs 24a to 24f is sequentially switched and extracted from the emission slit 30. FIG.
In FIG. 9, LEDs 24a to 24e as light sources or LE
Although the wavelength dispersion position 22 where the D24a to 24f are arranged is represented as a straight line, the light source array at the wavelength dispersion position 22 is not limited to a straight line, but may be a curved line or a light source arrangement in front and rear. It can also be an array.

[0016]

According to the present invention, a light source including a dispersion wavelength component at each position is arranged at a plurality of dispersion wavelength positions at a wavelength dispersion position assuming that a spectroscope is constituted by an optical system having a diffraction grating. In the spectrometer, the exit slit is arranged at the position where the entrance slit is arranged, and the light exiting from the exit slit is supplied to the photometric unit of the analyzer,
Since there is no mechanically driven part, the size and weight of the device can be reduced, and the cost can be reduced. Further, since a diffraction grating is used as the dispersion element, the wavelength purity of the extracted light is good.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of a conventional measurement device for clinical test.

FIG. 2 is a schematic front sectional view showing one channel of a photometric unit in the measuring device of FIG. 1;

FIG. 3 is a schematic sectional view showing one embodiment.

FIG. 4 is a diagram showing an emission spectrum of the LED 24a in the same example.

FIG. 5 is a diagram showing emission spectra of LEDs 24b to 24d in the same example.

FIG. 6 is a diagram showing an emission spectrum of the LED 24e in the example.

FIG. 7 is a view showing a spectrum of emitted light when the slit width of the exit slit 30 is set to 0.9 mm in the embodiment.

FIG. 8 is a view showing the spectrum of the emitted light when the slit width of the emission slit 30 is set to 0.5 mm in the embodiment.

FIG. 9 is a schematic sectional view showing another embodiment.

[Explanation of symbols]

 20, 20a Diffraction grating 22 Straight line at wavelength dispersion position in spectroscope 24a to 24e LED 26 Power supply device 28 Changeover switch 30 Emission slit

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masataka Hori 57th Higashikujo Nishiakedacho, Minami-ku, Kyoto-shi, Kyoto F-term (reference) 2G020 AA03 AA04 BA02 BA20 CB23 CB26 CB31 CB36 CB42 CB43 CC02 CC43 CD12 CD24 2G059 AA01 BB13 CC16 EE02 EE11 FF12 GG01 GG02 GG03 HH01 HH02 JJ05 JJ17 KK01

Claims (3)

[Claims] 1. A light source including an optical system having a diffraction grating as a dispersive element, and including a dispersion wavelength component at each of a plurality of wavelength dispersion positions assuming that the optical system constitutes a spectroscope. And a light source device in which an emission slit is arranged at a position where an entrance slit is arranged in a spectroscope, and light emitted from the emission slit is supplied to a photometric unit of an analyzer. 2. The method according to claim 1, wherein the light source is at least one of a halogen lamp, a hollow cathode lamp, an LED, and an LD.
The light source device according to claim 1, wherein the light source device includes a type. 3. The light source device according to claim 1, wherein the light source is sequentially switched and turned on, and the light having a wavelength corresponding to the dispersion wavelength at the wavelength dispersion position is sequentially emitted from the emission slit.