SU673953A1 - Reversible liquid compensator for optical device - Google Patents

Description

I

The invention relates to the field of optical instrumentation and can be used in surveying and geodetic instruments, such as theodolites.

The known optical theodolites are equipped with compensators for a vertical circle, however, in surveying theodolites intended both for mounting on a tripod and for hanging on consoles, compensators are not used because there are no devices reliably stabilizing the sighting line with low light losses and high quality images in both forward and reversed (i.e., inverted by 180 °) positions of the device 1.

Liquid compensators are known, having in a parallel beam of rays between two lenses a camera with a liquid and a rectangular prism directing light rays into a liquid at an angle of total internal reflection. These compensators reliably stabilize the line of sight with low light losses and high image quality, but they only work when the instrument positions 21 and b are straight (un-reversed).

Closest to the invention to the technical essence is a liquid compensator, which operates both in forward and in reverse positions of the device, containing in a parallel beam

between the two lenses, a camera with a liquid and a prism unit consisting of a rectangular prism, two half-prism located on the side wall of the camera. Additional reflective surfaces for light rays are

bottom and side of the chamber 4.

However, the known liquid compensator has large light losses due to reflection of semi-prism from the mirror surfaces and a long stroke.

rays in optical details. The image quality of the compensators may deteriorate with the passage of light rays through a thick layer of liquid in the chamber, due to the occurrence of temperature faults. In addition, the use of the known liquid compensator in theodolites with two-sided reading device is difficult.

The aim of the invention is to improve the image quality and the possibility of combining images of diametrically opposite parts of the limb of a vertical circle when used in bilateral reading devices.

This is achieved by the fact that in the proposed reversible liquid compensator, the optical unit is made in the form of a rhombus-prism, one of the faces of which is aligned with the transparent lower side of the chamber with a liquid, and the other face, which serves as a reflective surface, is connected to the upper side of the additional chamber with a liquid.

On the entrance faces of a rhombus prism, two Schmidt prisms are installed with a gap in such a way that their entrance faces are perpendicular to the reflecting facet of a rhombus prism.

Such a device makes it possible to create identical optical channels with low light losses and high image quality both in forward and in inverted positions of the device. It is also possible to combine images of diametrically opposite parts of the limb of a vertical circle.

FIG. 1 shows the optical circuit of the described liquid compensator.

in fig. 2 - the path of the rays in the compensator in the inverted position of the device;

in fig. 3 is an optical diagram of a compensator with two Schmidt prisms.

The liquid compensator (Figs. 1 and 2) contains lenses 1 and 2, in a parallel beam of rays between which there are chambers 3 and 4 with a liquid and a rhombus prism 5 made of glass, the refractive index of which is equal to the refractive index of the liquid. The limb plane of the vertical circle is in the front focus of lens 1, and the index / is located in the back focus of lens 2.

The liquid compensator (Fig. 3) contains lenses 1 and 2, Schmidt prisms 6 and 7, cameras with liquid 3 and 4 and a rhombus prism 5. The input faces of Schmidt prisms 6 and 7 are perpendicular to the reflecting facets of the diamond prism 5. Prism Schmidt is set as Thus, the gap between their faces and the output faces of the rhombus prisms is 0.1-0.2 mm. The points A and / 4, which are the diametrically opposite parts of the limb of the vertical circle, are respectively in the front focus of the lens 1 and the back focus of the lens 2.

The optical system of the compensator (Fig. II projects the image of the index / onto the plane of the limb 8 of the vertical circle at point I). In this case, the reflection of light rays from the liquid surface occurs in chamber 3, and the face of the rhombus prism facing the camera 4 serves as an additional reflecting surface. In the inverted position of the device (Fig. 2), the reflection of light rays from the liquid occurs in the chamber 4, and the diamond face facing the chamber 3 serves as an additional reflecting surface, thereby ensuring that the optical channels are identical to The compensator in the forward and reversed positions of the device. To ensure that the face of the diamond prism facing down is free from liquid, i.e. it is not wetted, an organophobic coating is applied to the reflecting edges of the diamond prism. organic matter such as triethylphenyl xylan or benzyl acetate. The thickness of the liquid layer in ampoules is about 1.5-2.0 mm.

The liquid compensator (Fig. 3) allows to combine images of opposite parts of the limb of a vertical circle located on the same horizontal diameter, i.e. point A is projected to point A + 180 °.

The condition of the compensator:

eleven ,

where f is the focal length of lens 1, equal to the focal length of lens 2 (Figs. 1 and 2);

R is the radius of the circle along which the divisions on the limb of the vertical circle are applied.

A liquid reversible compensator with low light losses and high image quality increases labor productivity and contributes to an increase in the accuracy of measurement of vertical angles by theodolites designed to work on a pit and in a raised position on

CONSO / 1I.

Claims (3)

1. Liquid reversible compensator for an optical instrument, mainly a theodolite, containing lenses and a fluid chamber and an optical unit between them in a parallel beam of rays, directing light rays to a liquid at an angle of total internal reflection, characterized in that image, the optical unit is made in the form of a rhombus-prism, one of the faces of which is aligned with the transparent lower side of the chamber with liquid, and the other face, which serves as a reflecting surface, is connected to the upper side additional chamber with liquid. 2. A compensator according to claim 1, characterized in that, in order to use & in double-sided reading devices, two Schmidt prisms are installed with a gap in the output faces of the rhombus prisms so that their input faces are perpendicular to the reflecting faces diamond prism. Sources of information taken into account in the examination. , 673953, 5O 1.Demlich F. Geodesic tools 3. Application for Germany No. 2152749 class 42 C 5/03 tov. M., “Nedra, 1970, p. 311-313,1974 2.Patent of Switzerland No. 3842244. USSR Copyright Certificate kl. 42 C 5/03, 1971. NO 517869, cl. G 02 B 5/06, 1975. .one