JPH09210899A - Optical apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable parallel measurement by one optical apparatus by providing the apparatus with a structure taking out the light emitted from the constructed part of the discharge path of a deuterium lamp from the front and the rear. SOLUTION: A deuterium lamp 1 being a light source has a structure capable of taking out light in two directions and has light taking-out windows 2, 2' and, even if the light emitted from the discharge constricted part of the lamp 1 is taken out in two directions, respective quantities of light are almost equal. The lights emitted in two directions are condensed to incident slits 4, 4' by concave mirrors 3, 3' and spectrally diffracted by concave diffraction lattices 5, 5. The spectrally diffracted monochromatic light is divided into two lights by half mirrors 6, 6' and the respective lights pass through emitting slits 7, 7' to pass through sample analyzing cells 8, 8' to be incident on photodetectors 9, 9' composed of photodiodes and converted to electric signals. The reflected lights from the half mirrors 6, 6' are used as reference lights and incident on photodetectors 10, 10' to be converted to electric signals. By this constitution, a double beam optical system of two systems is obtained and a measuring time can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spectrophotometer, a photodetector for a liquid chromatograph and the like, and more particularly to an optical device for improving analysis efficiency.

[0002]

2. Description of the Related Art As to the optical system of a spectrophotometer, as shown in FIG. 3, light emitted from a light source 12 is imaged on an entrance slit 14 at the entrance of a spectroscope by a concave mirror 13 or a lens. The light that has passed through the entrance slit reaches the concave diffraction grating 15 as it spreads, and is dispersed by the concave diffraction grating. A half mirror 16 for splitting into two directions, that is, the sample light side and the reference light side, is installed in the middle of the optical path after the spectrum with an inclination of 45 degrees with respect to the optical path.

One of the two split lights travels straight, is used as a sample light, and forms an image on the exit slit 17 as a monochromatic light. The light that has passed through the exit slit passes through the sample absorption cell 18 and enters the photodetector 19. The light bent by the other half mirror passes through the exit slit 17 ', enters the photodetector 20, and is used as reference light.

Since the optical system is as described above, it is difficult to improve the measuring ability, especially in a measurement such as a liquid chromatograph that requires a long time to measure one sample.

[0005]

In the prior art, the deuterium lamp used as a light source takes out light from one direction and constitutes an optical system, so that there is a limit to the measuring ability. Due to the improvement of the light source and the improvement of the optical system, It is to further improve the measurement capability.

[0006]

In order to achieve the above object, the present invention adopts a structure in which the light emitted in the narrowed portion of the discharge path of a deuterium lamp is taken out from the front and back as shown in FIG. Each obtains almost the same amount of light. As a result, it is possible to configure two optical systems without reducing the light amount, and it is possible to measure two samples simultaneously.

[0007]

FIG. 1 shows an embodiment of the present invention. 1
Is a deuterium lamp as a light source, which has a structure capable of extracting light in two directions and has light extraction windows 2 and 2 ′ each made of flat quartz. The light emitted from the discharge constriction part of the deuterium lamp has almost the same light quantity even if it is extracted in two directions, and even if compared with the conventional light extraction method, the same light quantity can be obtained, thus lowering the analysis sensitivity. There is no such thing.

The light emitted from two directions is concave mirror 3,
3 '(M1, M2) on the entrance slit of 4, 4' (S1,
The light that has been focused on S3) and has passed through the entrance slit is split by the concave diffraction gratings 5 and 5 '(G1, G2). The spectrally separated monochromatic light is transmitted to the half mirrors 6 and 6 '(HM1,
HM2) is divided into two, and the transmitted light of the half mirror passes through the exit slits 7 and 7 '(S2, S4), the sample analysis cells 8 and 8', and the photodetectors 9 and 9'composed of photodiodes. And is converted into an electric signal. The light reflected by the half mirror is used as reference light, is incident on the photodetectors 10 and 10 'composed of photodiodes, and is converted into an electric signal. With this configuration, a double-beam optical system with two systems can be obtained, so that the measurement capability is twice that of the conventional optical system, and the measurement time can be significantly shortened.

FIG. 2 shows an embodiment of an optical device using visible light. A halogen bulb 11 containing a halide is used as a light source, and an optical system similar to that shown in FIG. An optical system is obtained.

FIG. 4 shows an embodiment of an optical system for splitting the light emitted from one light source into two light beams. The light emitted from the deuterium lamp 12 is condensed by a lens 21, and the half mirror 22 is used.
Split into two light fluxes. The straight-ahead light forms an image on the entrance slit 23 and is split by the concave diffraction grating 24. The split light is split into two by the half mirror 25, and the straight-ahead light is incident on the photodetector 27 via the sample absorption cell 26. Half mirror 2
The light reflected by 5 enters the photodetector 28 and is used as reference light. The reflected light from one half mirror 22 is condensed on the entrance slit 29, is split by the concave diffraction grating 30, and the split light is split into two by the half mirror 31,
The straight traveling light is incident on the photodetector 33 through the sample absorption cell 32. The light reflected by the half mirror 31 is a photodetector 34.
To be used as a reference light. With the above configuration,
A double beam double beam optical system can be obtained, and the sample analysis efficiency can be improved.

[0011]

According to the present invention, it is possible to perform parallel measurement with a single optical device, and the measuring ability is doubled as compared with the conventional device. Further, by using a lamp having a structure capable of extracting light from the front and back, high analytical sensitivity can be obtained without reducing the light amount. Especially effective for liquid chromatographs and optical devices for medical equipment. Moreover, since only one light source is required, the cost of the device can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an optical system according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an optical system according to a second embodiment of the present invention.

FIG. 3 is an explanatory diagram of a conventional optical system.

FIG. 4 is an explanatory diagram of an optical system according to a third embodiment of the present invention.

[Explanation of reference numerals] 1 ... deuterium lamp, 2 ... plane window, 3 ... concave mirror, 4 ...
Incident slit, 5 ... concave diffraction grating, 6 ... half mirror,
7 ... Emitting slit, 8 ... Absorption cell, 9, 10 ... Photodetector, 11 ... Halogen bulb.

Claims (3)

[Claims] 1. An optical device comprising an optical system that splits light from a light source into two light beams or obtains light from two directions with one light source and disperses each light beam. 2. An optical device according to claim 1, wherein a deuterium lamp is used as the light source, light is taken out from the front and rear direction of the discharge constriction portion of the deuterium lamp, and light beams of two systems are separated respectively. . 3. The optical device according to claim 1, wherein the separated light is divided into sample light and reference light, and a sample measurement absorption cell is provided in the middle of the sample light side optical system.