RU2593639C1 - Method of aligning pancratic optical system - Google Patents

Abstract

FIELD: optics.

SUBSTANCE: method of aligning moving optical elements of pancratic optical system by groove diameter and undercutting of mounting plane of carriage for optical elements is carried out in two steps. First, by means of process grid fixed on a carriage, Zabelin tubes determine exact carriage position relative to spindle rotational axis, and then carriage is installed in aligning cartridge, which is fixed in machine spindle, and with help of aligning cartridge installing carriage accurately in such position that it occupies, positioned inside housing of POS. Control of accuracy of installation of carriage is performed by means of process grid and Zabelin tube.

EFFECT: high accuracy of aligning elements of pancratic system.

1 cl, 7 dwg

Description

The invention relates to optical instrumentation, in particular to a technology for manufacturing optical and optoelectronic modules with pan-optical optical systems.

In recent years, optical and optoelectronic complexes have been increasingly used, in which the optical systems of the optical and optoelectronic modules included in the complexes are made with variable focal length - pan-optical optical systems (POS). This is due to the fact that PICs have a number of significant advantages compared to optical systems with a constant focal length, which include:

- the ability to choose the optimal magnification and field of view;

- improving the efficiency and ease of use during operation;

- reducing the number of required modules required to solve the tasks.

At the same time, POS in the design and production plan are complex optical-mechanical systems in which it is necessary to center optical components with high accuracy - lenses in a frame.

In most modules, the movement of optical components is carried out using sliding bearings, which are used as precision machined cylindrical surfaces of stationary housings and frames of movable optical components, or guide pins [L.I. Krynin, “Fundamentals of Designing and Centering Variable Focus Lens,” textbook, ITMO (State University), St. Petersburg, 2008, section 1; US patent US 8634138, G02B 27/646 from 01/21/2014 (publication date 02/10/2012)].

For such designs, methods for node-by-center alignment of optical systems using special technological equipment such as: Zabelin tube for determining the errors of the exhibition of optical components, a centering cartridge for their high-precision installation, a precision machine for trimming the seats of nodes with optical components [Site www.555nm.ru] have been developed [Website www.555nm.ru , section “Articles”, file “Analysis of lens centering methods”, subsection 4.5].

A known method of centering the lens using a centering cartridge with a shift and rotary parts, mounted in the spindle of the lathe, and a Zabelin tube installed in the tailstock of the machine, includes sequential centering of each of the lens surfaces relative to the axis of rotation of the spindle [RF Patent 2442124, G01M 11/00 , G01B 11/27].

According to the above method, when centering a multicomponent lens, based on structural or technological considerations, one of the lens surfaces is selected, the lens is mounted so that, by choosing the length of the technological part of the frame or using remote bushings, the autocollimation point of the selected surface lies in the same plane with the center of curvature the rotary part of the centering cartridge lying on the axis of rotation of the spindle. The autocollimation point of the selected surface is combined with the center of curvature of the rotary part of the centering cartridge by moving the shear part of the cartridge. The autocollimation point of the other lens surface is combined with the axis of rotation of the spindle by moving the rotary part of the cartridge while maintaining the same position of the autocollimation point of the selected lens surface, previously aligned with the center of curvature of the rotary part of the cartridge.

This method is not applicable in PIC, in which optical components are mounted on carriages with rolling bearings. The use of rolling bearings is caused by the fact that when operating optical modules under severe external influences: temperature gradients, mechanical shocks and vibrations, sliding bearings wear out quickly, which leads to a decrease in the quality of the optical image and / or breakdown of the entire module.

In such constructions, the carriages are moved inside a precisely made cylindrical cavity of the PIC body along its axis. To eliminate play during the movement of the carriage, one of its bearing assemblies is pressed by a spring to the surface of the cylindrical cavity. This leads to the appearance of an additional degree of freedom of the carriage in the radial direction. Backlash in rolling bearings and the presence of a degree of freedom of the carriage in the radial direction make it impossible to accurately (a few microns) trim on the machine the landing surfaces of the carriage installed in the cylindrical cavity of the POS body.

The purpose of the present invention is to provide a method for centering a pancratic system, the optical components of which are moved inside a cylindrical guide surface on rolling bearings, using traditional high-precision technological equipment.

The essence of the proposed method lies in the fact that using the precision machine, Zabelin tube and technological grid mounted on the carriage, the position of the carriage installed in the guide cylinder of the PIC housing is determined. Then the carriage is removed from the POS body, fixed in a centering cartridge, which is installed in the spindle of a precision machine. Then, using the Zabelin tube, a technological grid fixed to the carriage, and a centering cartridge, the carriage is set to the position exactly corresponding to its position, which the carriage occupied inside the PIC body. The position of the carriage is controlled by the image of the technological grid and the autocollimation image from its surface of the crosshairs of the Zabelin tube. Then turn on the machine and trim the landing surfaces of the carriage.

The method is characterized by the following operations:

- fix the POS body in the machine spindle coaxially with the spindle axis;

- fix the frame with the technological grid on the carriage;

- insert the carriage with the technological grid into the POS body fixed in the spindle of the machine;

- fix the Zabelin tube in the tailstock of the machine;

- find the autocollimation image of the crosshairs of the Zabelin tube from the surface of the technological grid and by turning the spindle of the machine along the measuring grid of the Zabelin tube, the beat diameter of this image is determined;

- find the image of the technological grid and by rotation of the spindle of the machine using the measuring grid of the Zabelin tube measure the diameter of the beating image of the technological grid;

- remove the carriage from the PIC housing and fix it in the centering chuck, which is installed in the spindle of the machine;

- by rotating the machine spindle, set the diameter of the runout of the self-collimating image of the cross of the Zabelin tube from the surface of the technological grid using the centering cartridge, as well as the diameter of the runout of the image of the technological grid, equal to the previously measured diameters and center of beats of these images. The diameters of the beats are controlled by the measuring grid of the Zabelin tube;

- start the machine and trim the landing surfaces of the carriage.

An example implementation of a method for centering a pan-optical optical system is shown in the drawings. In FIG. 1 schematically depicts a set of technological equipment and its condition, necessary to determine the diameters of the runout of the image of the technological grid and the self-collimation image of the crosshairs of the Zabelin tube from its surface. In FIG. Figure 2-4 shows the possible types of grids: technological (Fig. 2), the crosshairs of the Zabelin tube (Fig. 3) and the measuring grid of the Zabelin tube (Fig. 4). In FIG. 5 shows the positions of the autocollimation image of the crosshairs of the Zabelin tube reflected from the surface of the technological grid 3, and FIG. 6 - positions of the image of the technological grid on the measuring grid of the Zabelin tube at various angles of rotation of the spindle of the machine. In FIG. 7 schematically shows the state of the technological equipment necessary to set the runout diameter and the position of the self-collimation image of the cross of the Zabelin tube and the image of the technological grid reflected from the surface of the technological grid for the final processing of the carriage landing surfaces.

As technological equipment, a high-precision lathe, centering chuck, Zabelin tube, technological grid are used.

The implementation of the method of centering PIC is carried out in two stages. The first stage begins with the installation of technological equipment (Fig. 1). The Zabelin tube 1 is fixed in the tailstock of the machine, a technological grid 3 is installed on the carriage 2 (an example of the technological grid 3 is shown in Fig. 2). The carriage 2 is inserted into the body 4 of the PIC, which is fixed in the spindle 5 of the machine. The carriage 2 has the ability to move along a precision-made cylindrical surface 6 of the housing 4 on the rolling bearings 7. Then, through the eyepiece 8 of the Zabelin tube 1, an autocollimation image of the crosshairs of the Zabelin tube is reflected from the surface of the technological grid 3 (an example of the crosshair of the Zabelin tube is shown in Fig. 3, and measuring grid of this tube - in Fig. 4).

Next, manually rotating the spindle 5 of the machine, observe in the eyepiece 8 circular movements of the self-collimation image of the crosshairs of the Zabelin tube reflected from the surface of the technological grid (Fig. 5). Using the measuring grid of the Zabelin tube, the diameter Dtz of the circular movement of the self-collimating image of the crosshairs of the Zabelin tube is determined and stored, the reference position of the autocollimation image, for example, the highest position of the autocollimation image, is selected and stored. Then, observing through the eyepiece 8, the image of the technological grid 3 is found and the reference position of its center Ot is stored, the diameter of the circular movement of the image of the technological grid along the measuring grid of the Zabelin tube is measured (Fig. 6). After completing these operations, the carriage 2 is removed from the body 4 of the PIC. At this point, the first stage of the implementation of the method ends.

The second stage of the method implementation begins with the installation of the carriage 2 in the centering cartridge 9 (Fig. 7), which is fixed in the spindle 5 of a precision machine. The alignment cartridge 9 has a two-axis linear displacement assembly 10 with displacement screws 11, 12 and a two-axis inclination assembly 13 with inclination screws 14, 15.

By manually rotating the machine spindle 5, the screws 14 and 15 of the tilt assembly 11 of the centering cartridge 9 along the measuring grid of the Zabelin tube set the reference diameter of the self-collimating image of the Zabelin tube grid equal to the previously measured value Dtz at the reference position of the autocollimation image from the surface of the technological grid 3 (Fig. 5 )

By manually rotating the machine spindle 5, the screws 11 and 12 (Fig. 7) of the linear displacement assembly 10 of the centering cartridge 9 along the measuring grid of the Zabelin tube are set at the reference position of its center Ots, the diameter of the image of the technological grid equal to the previously measured value of Dс (Fig. 6) .

Next, turn on the machine and process the cylindrical landing surface 16 and the end landing surface 17 of the carriage 2 (Fig. 7) under the optical elements of the pic.

In a similar way, the remaining movable optical components included in the PIC are centered.

Claims (1)

A method of centering a pan-optical optical system (POS) by grooving the landing diameter and trimming the landing plane of the carriage for optical elements moved on rolling bearings, characterized in that the position of the carriage inside the guide surface of the PIC body is precisely determined using a technological grid mounted on the carriage and Zabelin tube relative to the axis of rotation of the spindle of the machine, and then remove the carriage from the body of the PIC, install it in the centering cartridge, which is fixed in the spindle st Anka, and with the help of a centering cartridge, a technological grid and a Zabelin tube, the carriage is placed exactly in the position that it occupied while inside the POS body.

Images