DE1927822U - LIGHT FIELD SHUTTER FOR MICROSCOPES. - Google Patents

Description

DOLPING. W. PAAP Γ. H. 4 Ö UJ JJ / * 1 O. dv DO 32652 W \

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MünGhen, the Λ3 * 9 '

C. Reichert Optische Werke Aktiengesellschaft, Wieh "(Austria)

Illuminated cover for microscopes - '- - ' ... 'Utility model registration'

It is known to introduce light field diaphragms and aperture diaphragms in the microscope. The former lie in one to the object plane, the latter in one to the plane of the exit pupil of the microscope

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objective corrective level. lifelong. the. Aperture diaphragms are occasionally also designed in such a way that any given light distribution is realized in the exit pupil Illuminated field diaphragms always set up so that they only cover that part of the object to be illuminated in the field of view of the microscope it appears. Will - namely unnecessarily; also.the environment of the observed point is illuminated, parts of this light get into the field of vision through scattering in the object and form there one that more or less deteriorates the image contrasts Veil. An illumination beam path that takes these conditions into account (so-called Koehler's lighting) therefore contains one Field diaphragm, which by means of the. Iffikröskopkondensors, und with the aid of further optical elements in the

Object level mapped tmd: is usually 'chosen' to be large. that the image of its opening just coincides with the diameter of the field of view. Then the field of view / bright5 appears Surroundings remain unlit. ■

In particularly delicate cases, however, one becomes ¹ 'the luminous field;. aperture an even smaller diameter, ie- want to narrow the illuminated IPeId even further, Vim to further increase the contrast-enhancing effect and only see a small middle object area, but this with the best possible contrast rendition. Such a lall is, for example, in given to the photomicrograph of very low-contrast objects. Another aspect is microphotometry, when the absorption or reflectivity of very small object details is to be measured quantitatively. No further explanation is required, that in this case the scattered light not only disturbs subjectively, but causes a measurement error. - - ^:. ". ■ -.""■ -.-

Draws, one now the field diaphragm so far that it releases only a very small part of the field, it will be difficult to focus on the object _to: orient to find a particular passage or rediscover, weil.jede Overview missing. Open the diaphragm to see the suffering and close the diaphragm to take pictures or. Measuring is an inexpedient way out for routine work. This procedure is cumbersome and time consuming and irritates the observer by the constant. Light intensity change. . ... ^: - ~ ~ _ . ....

The aim of the present / fire is a flare screen for microscopes, .that that ..scattered light-practical

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turns off, but still overlooks the field of view enables. - .- -...-. . . ", - - /" "" -.-. ".- .: ■ '■

According to the innovation, this object is achieved by a luminous field diaphragm which is characterized in that the diaphragm parts which restrict the light flux and which are usually opaque have a slight transparency Aperture parts of slight transparency by covering a transparent one. Carrier plate with absorbent, but partly permeable material or produced by vapor deposition of partly permeable thin layers of metallic and / or non-metallic substances on a transparent carrier plate. _: ■

Apertures according to the above basic ideas can be particularly simple as a perforated panel, i.e. as a panel-given - Execute opening. If you want to change the aperture; so you can place diaphragms with different openings on a replacement device, like a slider or a turntable. However, the field diaphragm can also be "turned off" in a particularly advantageous manner mutually adjustable, produce the "light flow on different cross-section constricting elements.

In the embodiment of the Pig. 1 means 1 is a carrier plate made of mirror glass, the middle part 2 of which is clear, while the rest of the diagonally hatched part 3 is covered with a chemically deposited silver layer, which is so thin / chosen that it has a permeability of about 0.5 % owns. If this aperture with a suitable reduction in the field of view,

this purity is indicated by the dashed line; Ere fs'4; is, shown, so is enough. with the usual lighting with -: low-voltage lamp, the illuminance reduced to 0.3%, to also in the. Part 3 clearly recognizing the object structure .. "■" ~ "and being able to orientate oneself, while the -intensity- of the scattered light is so attenuated that it only causes negligible! Errors.", -. _^·::: - "- ■..

Another option is to _den. Part 5 in Fig. 1 in a high vacuum with very thin,. ". A ... interference filter forming layers to be covered Materials and their thicknesses are known to exist in the hand to realize any desired degree of transparency as a function of the light wavelength. V ■■ .- ■ "": ■ "-

Finally, Pig shows. 2, how a partially transparent field diaphragm of variable cross-section can be realized. 1 and 1 'are support glass plates, to which a thin Chromschxcht was vapor-deposited with a permeability of about 0.7% so that they hatched _obliquely. with 2 and 2 · denotedeii ..... covers area proportions. If one pushes the two plates one above the other in the direction of the arrows · -, the angular covering parts form a diaphragm square of adjustable edge length. ...-

Claims (5)

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