SU366350A1 - OPTICAL ANGLE DEVICE - Google Patents

Description

This invention relates to the field of angular measurements. It can be used in optical dividing heads, in optical dividing tables and other goniometers with double-sided combined reading.

An optical goniometric device is known, which contains an illuminator, a circular chrome with dashes installed during light rays, and a system for combining strokes and for counting.

In order to increase the accuracy of the nominal alignment, the scale marks are made double (bifillary).

Two-sided reading eliminates the de-centering of the dial scale to a certain extent, eliminating all odd harmonics of systematic errors. However, the remaining errors — even harmonics of systematic errors (mainly the second harmonic), together with random errors that are not subject to any regularity and periodicity, turn the manufacture of high-precision goniometers into a very serious technical problem, the solution of which takes a lot of work and does not always succeeds. All these errors reduce the measurement accuracy.

The proposed device is different from

known for the purpose of improving the measurement accuracy, the dial scale has single strokes, and the device is equipped with a single lens and prism system for artificially forming double strokes in the plane of the dial by projecting single strokes of one zone of the scale into single strokes of another zone located relative to first at 90 °.

In this way, the image is also rotated by 90 °, and the image of the projected strokes of the first diameter turns out to be parallel and close to each other with a slight transverse shift with the strokes of the second diameter, thus forming a bifillary stroke. Combined counting in the field of view is obtained by known methods.

FIG. Figure 1 shows a scheme for the formation of bifilary strokes; in fig. 2 is a general optical system forming a combined sample.

The device contains (see Fig. 1) an illuminator in the form of a light source / and a capacitor 2; dial scale 3 with single strokes; a single lens and prism system comprising prisms of 4, 5, 6, 7-c lenses of the objective S and 9; a system for combining strokes and for reference (see FIG. 2), including a lens 10, a compensating lens 11,

prism prism unit with line section and microscope 13 for observation (projection device).

The device works as follows.

The light source / through the capacitor 2 and the prism 4 illuminates the strokes located at the end of the dial 3 of the dial 3. This diameter will be called the diameter D1. Krugova SCHKala has single strokes (not bifillary).

The prism 5 changes the direction of the rays by 90 °, perpendicular to the diameter D The prism 6 directs the beam of rays parallel to the diameter D, and the prism 7 to the plane of the dial scale in the area of the diameter turned 90 °. This diameter is conventionally referred to as the diameter D. A lens, consisting of lenses S and 9, gives an image of the strokes of diameter D with increasing 1- in the area of diameter D2. This image will be rotated 90 ° with this application system, i.e., it will be parallel to the strokes of diameter D2, and the necessary interval between the strokes will be provided by the alignment of the system.

Thus, in the area of the diameter D2, a bifillary stroke is formed, consisting of a real line of diameter Yes and an image of the line of diameter D2. Similarly, we obtain a bifillary line in another branch of the system.

In the process of nonial alignment of strokes, when the limb is set at a given angular position, strokes of four zones are involved (strokes are located at the ends of two diameters rotated 90 ° relative to each other). This feature eliminates, in addition to the influence of odd-modem, the influence of the fundamental even first harmonic of systematic log solutions.

The probability of compensation increases.

random errors in sign, and, consequently, in magnitude. Counting shows that if, with the usual two-sided reading, the probability of compensation by the sign of random

The errors of combining strokes located at the ends of a single diameter with respect to zero are 50%. When used to align strokes located at the ends of two diameters located at 31 significant angular distances between themselves, the probability of compensation for the sign of random errors increases to 87, five%. These two advantages of the proposed system make it possible to obtain goniometers with particularly high accuracy with much less difficulty. As for some complication of the design due to the addition of a single lens and prism system, it pays for itself with a simpler dividing technology (the scale does not have bifilar strokes, but single) and by reducing the labor costs of changing the dial scale due to insufficient accuracy.

Subject invention

Optical goniometric device containing an illuminator, a dial with strokes installed during the light rays,

and a system for combining strokes and for reference, characterized in that, in order to improve measurement accuracy, the dial scale has single strokes, and the device is equipped with a single lens and prism system for artificially forming double strokes in the plane of the dial scale by projecting single strokes of one zone scale in the area of single strokes of another zone, located 90 ° relative to the first.

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