JPS5952767B2 - Slit for spectrophotometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In a spectrometer, it is essential to open and close the entrance and exit slits with equal dimensions, and it is preferable that the mechanism be as simple as possible and operate as accurately as possible.

FIG. 1 is a diagram showing the optical system of a multispectral beam.

A light beam incident from a slit 1 is reflected at right angles by a mirror 2, and then reflected by a collimating mirror 3 to become a parallel light beam and enter a dispersion element 4 such as a diffraction grating. The light separated by the dispersion element 4 is condensed again by the collimating mirror 3, and is then focused by the mirror 5.
and is reflected by mirror 6, producing a spectrum in intermediate slit 7. The light that enters the second spectrometer through the slit 7 is dispersed again and exits from the slit 8 as highly pure monochromatic light. As mentioned above, three slits are used in this spectrometer, and the slits are arranged at right angles to each other or on a straight line.

These slits must be opened and closed in conjunction to provide equal spacing. Conventionally, when slits 1 and 7 are arranged at right angles with a certain distance, as in the case of slit 1 and 7 in FIG. 1, they have often been connected by a complicated gear mechanism. In this case, a means for compensating for the backlash of the gear must be used, necessitating a more complicated mechanism. Furthermore, when the slits are arranged in a straight line, the light source and the sample chamber must be placed on opposite sides of the spectrometer, resulting in inconveniences such as the need for a large installation space. An object of the present invention is to provide a slit for a spectrophotometer that can reliably operate a plurality of slits installed in a complicated positional relationship with a relatively simple mechanism.

The main points of the present invention are two thin plates having windows arranged one on top of the other, two holding plates to which these two thin plates are respectively attached, and leaf springs attached to both end faces of each of these two holding plates. A U-shaped fixture with this leaf spring attached to two parallel sides,
A stand plate that attaches the non-parallel sides of this fixture, a lever that rotates parallel to the surface of this stand plate, two pins attached to the top and bottom of this lever, and a hole made in the middle position between these two pins. and a mounting screw that engages and rotatably fixes the lever to the stand plate. This will be explained below based on the drawings.

FIG. 2 is an explanatory diagram of the structure of a slit according to an embodiment of the present invention.

The thin plates 11 and 12 are metal plates having a thickness of 0.05 to 0.1 mm, and are provided with windows 14 and 15 at four corners, respectively. The thin plates are fixed to the holding plates 16 and 17 with adhesive or screws, respectively. Leaf springs 18 are attached to both end surfaces of the holding plate, respectively, and the leaf springs 18 are attached close to two parallel sides of the U-shaped fixture 19. In this way, two thin plates 11,
12 overlaps windows 14, 1 with a gap of 0.05 to 0.1 mm.
If it is provided appropriately at position 5, a vertically long slit will be formed. For example, the minimum usable width of the slit is set when the leaf spring 18 is not deformed. The fixture 19 is fixed to a stand plate 20 made of a thick steel plate and installed on the bottom plate of the spectrometer. The stand plate 20 has a protrusion 22 to which the lever 21 is attached with a mounting screw 25. Since the sliding surface 26 of the mounting screw 25 fits into the lever 21, pulling the steel wire 27 attached to the lower end of the lever 21 will rotate the lever 21 left and right, and the upper pin provided on the lever 21 will rotate. 23. Move the lower pin 24 in the opposite direction. As shown in FIG.
has a notch 29 and a hole 30, and the upper pin 23 has a notch 2
9 and is tightly fitted into the groove 28 of the retaining plate 17. On the other hand, the lower pin 24 passes through the hole 30 and the lower notch of the retaining plate 17 and is tightly fitted into the groove 31 of the retaining plate 16. In the slit assembly having the above structure, when the steel wire 27 is pulled in the direction of the arrow, the lever 21 rotates to the right, the upper pin 23 moves to the right, the lower pin 24 moves to the left, and the thin plate 1
2 to the right and the thin plate 13 to the left. Therefore window 14
and window 15 is formed. The width of the slit will increase. On the other hand, if the steel wire 27 is pulled to the right, the slit width is reduced and the light beam 32 can be completely blocked. This situation is shown in Figure 3. At this time, since the leaf spring 18 is smoothly bent, the movement of the slit width is smooth, and no play occurs when the slit width is increased or decreased. Moreover, this change in slit width is of course double-sided, and its reproducibility is good. FIG. 4 is a plan view when the slit mechanism shown in FIG. 2 is applied to the double spectrometer shown in FIG. 1. This slit combination has three slits arranged at right angles and in a straight line. A slit mechanism for such a slit arrangement is relatively easily made possible by the present invention. The levers 21 of the slit 1 and the slits 7 and 8 are connected by a steel wire 27, and a pulley 34 attached to a pulley mount 33 is used at a place where the lever 21 is bent at a right angle.

Although not shown in this figure, if either end of the lever is displaced with a cam, rod, steel wire, etc., the
The widths of the two slits can be increased or decreased by the same size at the same time, making them completely interlocked. Since the slits 7 and 8 are formed from a common thin plate, a single slit mechanism can achieve the purpose. As described above, according to the present invention, 1. The slit width can be increased or decreased using the deflection of the leaf spring, so it can be operated with a small force (experimental results 10
A force of about 0g is sufficient).

Further, the operation when switching between opening and closing directions is smooth, there is no need to compensate for gear backlash unlike when using a conventional gear mechanism, and maintenance is easy. 2. With this slit mechanism, the slit width can be made extremely narrow to zero without damaging the cutting edge, making it convenient for centering during optical adjustment.

This was impossible with conventional slits in which the cutting edges were opposed because it would damage the cutting edges. However, although the slit of the present invention creates a gap of about 0.05 mm between two thin plates, this does not cause any problem since the slit width during actual measurement is often 0.5 mm or more.

[Brief explanation of the drawing]

Figure 1 is a diagram of the optical system of a double spectrometer, Figure 2 is an explanatory diagram of the structure of a slit that is an embodiment of the present invention, Figure 3 is an illustration of how the movement of two thin plates changes the slit width, and Figure 4 is an illustration of the slit width. 2 is a plan view in which the slit mechanism of FIG. 2 is applied to the double spectrometer of FIG. 1. FIG. 1, 7, 8...Slit, 2, 5, 6...Mirror 3
... Collimating mirror 1, 4 ... Dispersion element, 11,
12... thin plate, 14, 15... window, 16, 17...
・Holding plate, 18... Leaf spring, 19... Fixing metal fittings, 2
0... Stand plate, 21... Louver 23... Upper pin, 24... Lower pin, 25... Mounting screw, 27...
・Steel wire, 28, 31...groove, 34...pulley.

Claims (1)

[Claims] 1. Two thin plates with stacked windows, two holding plates to which these two thin plates are attached, leaf springs attached to both end faces of these two holding plates, and a plate spring that is parallel to each other. A U-shaped fixture attached to two sides, a stand plate to attach the non-parallel sides of this fixture, a lever that rotates parallel to the stand plate surface, two pins attached to the top and bottom of this lever, and this A slit for a spectrophotometer, characterized in that the slit for a spectrophotometer is provided with a mounting screw that fits into a hole provided at an intermediate position between the two pins and rotatably fixes the lever to the stand plate.