SU444054A1 - Device for the projection of the target mark into the observation system of the measuring device - Google Patents

Description

one

The invention relates to a photogrammetric instrument making and can be used in measuring devices that implement the principle of measuring an object or its image using a target mark.

In order to ensure optimum sighting conditions, it is often necessary to make the target marks interchangeable — different in shape, size, etc. The main requirement arising during the change of marks is the need to ensure the identity of the position of their images in the field of observation systems with permissible displacements not exceeding a few nanometers.

The known devices for introducing replaceable luminous target marks contain a revolving disk with a mark, alternately introduced into the optical amplification system. The value of

The displacements of the stamps when switching them are entirely determined by the quality of manufacture and assembly, as well as the degree of wear of the revolving device. Indeed, these displacements will occur due to

inequalities in the distance from the marks to the center of rotation of the revolving disk, the angular displacements of the marks relative to their respective retainer slots, from the elevators in the axis of rotation of the disk and in the retainer. As a result of the addition of these errors, the displacement of the image of the marks is much higher than the magnitude of the error. both stereoscopic and monocular sightings and significantly reduce the accuracy of measurements,

Particularly great difficulties arise when creating a brand changer device in stereophotogrammetric instruments that have pancratic observation systems and work with different magnifications in their right and left branches, since the value of the right and left marks should be the same.

The purpose of the invention is to improve the measurement accuracy of the device.

In the proposed device, due to the complexity of the collimating system, all mechanical defects of the brand switching device do not fundamentally cause

The picture of their images and tolerances

the manufacture of parts and the assembly of the revolving device may be increased tenfold compared with the tolerances on

revolving devices of brands in known prototypes. In the proposed device, instead of switching marks before the general

the collimating lens switches, only parallel beams of rays, each of which carries an image of only one brand and is formed by a separate lens for each brand. This allows both the marks and the corresponding lenses to be fixed and rigidly attached to the body of the instrument, which not only facilitates their proper adjustment,

but also ensures long-term preservation of this adjustment. Since the switching is performed in parallel beams, the linear displacements of these beams and, consequently, the linear displacements of the moving parts of the device lose value; The angular displacements of parallel beams can be easily eliminated if known types of prisms are used for switching beams, for example rhombic, which, as is well known, do not cause angular displacements of the beams emerging from them at different turns of these prisms.

- The brand lighting system is not critical. Structurally, it is easiest to illuminate all brands from one light source by switching on the light; A strong beam of rays is similar to the way the beams of rays emanating from collimators are switched.

The drawing shows a diagram of one of the possible variants of the proposed device.

The device includes a housing 1 of the device, an incandescent lamp 2, the first common component 3 of the condenser system, a replaceable color filter 4, used at | the need to obtain a color image of the mark, the prism of the 5 switch illuminated. the second component 6 condenser (Systems, separate for each brand, fixed disk 7 with components 6,

transparent marks 8 on an opaque background fixed disk 9 with marks 8, collimating lenses 10, fixed dis 11 with lenses 10, prism 12 switching output parallel beams, axis 13 of joint rotation of prisms 5 and 12 rigidly fixed on this axis, latch 14 axis 13, lens 15 projecting images of marks in the field of view of the instrument’s observing system.

Components 6, marks 8 and lenses 10 should be located approximate concentric to axis 13, marks 8 should be aligned with the focal planes of 1O lenses, and the sighting axes of all collimators formed by them should be aligned for strict mutual parallelism by the methods used in adjusting binocular optical systems, for which either the brand or the lenses must have appropriate centering devices.

The switching of marks is carried out by turning the knob, which is located at a convenient place for the observer and is connected by a drive to the axis 13.

Subject invention

A device for projecting the target mark into the observation system of a measuring device, containing a set of marks of the desired shape and size, collimating lenses by the number of marks, a projection lens and an illuminator, characterized in that, in order to improve measurement accuracy, the marks are rigidly connected to the collimating lenses, together with the collimating lenses along the formative circular cylinder, and between the illuminator and the collimating lenses there is a prism like a diamond prism or a diamond prism with a roof rotatable.