JPS634649B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spectrophotometer that can cover a wide wavelength range.

When performing spectroscopic analysis over a wide wavelength range with a spectrophotometer, one type of light source cannot cover the entire measurement wavelength range, so multiple types of light sources are used and the optical path is switched at an appropriate wavelength position in conjunction with wavelength scanning. The light from that light source is guided to a spectrometer. In this case, the plurality of light sources are left on and only the optical path is switched. It takes time for the light emission from the light source to stabilize. For example, with a deuterium lamp (D2 lamp), which is often used as a light source in the short wavelength range, it takes several to 10 seconds for the light emission to stabilize after being turned on, so stop measurements during this time. This is because, in the case of automatic measurement, the control device becomes complicated, and repeated blinking of any light source, regardless of the type, shortens the life of the light source. However, if the light source is turned on continuously, the remaining life time will be shortened. The present invention was made with the aim of solving such inconveniences.

The present invention has two light sources and an optical path switching mirror that switches the respective lights and guides them to a spectrometer, and includes means for setting wavelengths at both ends of an arbitrarily selected measurement wavelength range, a light source switching wavelength setting means, and a light path switching mirror that switches the respective lights and guides them to a spectrometer. A means for determining whether the wavelengths at both ends of the range are both on one side of the light source switching wavelength or sandwiching the light source switching wavelength, and lighting control for lighting only one or both of the two light sources depending on the determination result. A spectrophotometer is provided. The present invention will be explained below with reference to Examples.

FIG. 1 shows a spectrophotometer according to one embodiment of the present invention.
D2 is a deuterium lamp that handles measurements in the short wavelength range;
W is a tungsten lamp that performs measurements in the long wavelength range. C is an optical path switching mirror, and two lamps D
2. W is in a symmetrical position with respect to this mirror C, and when C is at the dotted line position, the light from D2 enters the condenser mirror M, and when C is at the solid line position, the light from D2 is blocked. , W are reflected by C and incident on a condenser mirror M. S is an input slit of the spectroscope, and the light from the lamp D2 or W reflected by the condenser mirror C is focused onto the slit. The configuration of the spectrometer itself may be of any known type.

The above is the optical configuration of the spectrophotometer of the present invention.
The block diagram in FIG. 1 shows the configuration of the control system of the spectrophotometer of the present invention. Reference numeral 1 denotes a wavelength scanning driving device for the spectrometer, which is composed of a pulse motor, a pulse oscillator, a counter, and the like. Lmx is a register of the long wavelength end setting means of the measurement wavelength range. Lmi
is a register of the short wavelength end setting means of the measurement wavelength range. Each wavelength data is manually input into these registers via the ten-key device T and the input device I. Lch is a register of a light source switching wavelength setting means, and data is also inputted to this register via the numeric keypad T and input device I. J is the long wavelength end wavelength λmax set to Lmx, the short wavelength end wavelength λmin set to Lmi, and the switching wavelength λch set to Lch in the determination circuit.
A signal is output to terminals d and w. The relationship between the magnitude of each wavelength and the output signals of the terminals d and w is as follows when λmin≦λch: d output 1 λmin>λch 0 λmax<λch w output 0 λmax≧λch 1. 2 is a lighting control circuit, the D2 lamp lights up when the d terminal output is 1, the D2 lamp goes off when the same output is 0, and the W lamp lights up when the w terminal output is 1, and the same output is 0.
Press to turn off the W lamp. The above relationship is illustrated in FIG. 2. 3 is a central control unit that program-controls the entire control system. The central controller controls the wavelength scanning drive device to perform wavelength scanning in a predetermined wavelength range based on the data in registers Lmx and Lmi, compares the wavelength position of the spectrometer with the data in register Lch, and switches the optical path when they match. The driving device 4 for the mirror C is activated to move the mirror C back from the solid line position in FIG. 1 to the dotted line position when the scanning wavelength is moving from a long wavelength to a short wavelength.

The spectrophotometer of the present invention has the above-described configuration, and in the case of FIG. 2A, the scanning wavelength range is on the shorter wavelength side than the light source switching wavelength λch, and in this case, the tungsten lamp W is unnecessary, so only the D2 lamp is turned on, and the same procedure is performed. In the case of Fig. 2 C, only the tungsten lamp W is lit, and both the D2 lamp and the tungsten lamp are lit simultaneously only when the scanning wavelength range straddles both sides of the light source switching wavelength λch, so that lighting switching is not performed. I have to. In this way, the lamps are not turned on unnecessarily, so shortening the lamp life due to unnecessary use can be avoided. Also, when the scanning wavelength range straddles both sides of the light source switching wavelength, both lamps can be turned on in parallel. Unlike switching the lighting of two light sources in conjunction with switching the optical path, the lighting status of the light source is sufficiently stable, and the measurement operation can proceed without interruption, reducing the lamp life caused by blinking. Shortening is also prevented.

Now, in the present invention, the register shown in FIG.
Lmx, Lmi, and Lch are necessary parts in a conventional spectrophotometer for wavelength scanning and optical path switching, and the same applies to the driving device for the optical path switching mirror C. Therefore, since the present invention utilizes the functional parts that are also present in the conventional device described above and performs lighting control as shown in FIG. 2, the device is hardly complicated and the length of the light source can be reduced It has the feature that it can simultaneously achieve both effects of extending the lifespan and eliminating the need for the operator to turn on and off the light source.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the main parts of an apparatus according to an embodiment of the present invention, and FIG. 2 is a graph showing the operation of the apparatus. D2... Deuterium lamp, W... Tungsten lamp, C... Optical path switching mirror, M... Concentrating mirror, S...
Spectrometer entrance slit.

Claims (1)

[Claims] 1. A means having two light sources and an optical path switching means for switching the light from each light source and guiding it to a spectrometer, and setting wavelengths at both ends of an arbitrarily selected measurement wavelength range;
a light source switching wavelength setting means; a means for determining whether both end wavelengths of the measurement wavelength range are on one side of the light source switching wavelength or on both sides of the light source switching wavelength; A spectrophotometer comprising a lighting control means for lighting only one or both at the same time.