SU1679453A1 - Mechanism for changing the focal distance of pancratic lens - Google Patents

Abstract

The invention relates to optical instrumentation and can be used in lenses with significant movement of optical components. The purpose of the invention is to simplify the manufacture of lenses while improving the image quality of the lens. The mechanism for changing the focal distance of a pancreatic frame includes frames with optical components, of which it is stationary, the second is mounted for movement along the optical axis, and a third is capable of moving together in the opposite second direction, spatial cams in the form of two coaxially and rigidly articulated multi-turn running screws, made with standard thread of different pitch and direction of cutting, flat cam (cam) and two-armed lever. Moreover, the second component is connected directly to the driver, which is a nut on one lead screw, and the third component is connected to the nut of the second lead screw through one arm of the double-arm fixed on it and simultaneously with the flat cam through the second arm of the lever. 3 il. J

Description

The invention relates to optical instrumentation and can be used in lenses with significant movements of optical components.

The aim of the invention is to simplify the manufacture of the lens while improving the image quality.

Fig. 1 shows the structure of the mechanism; Fig. 2 illustrates the dependence of the movement of one movable component on the movement of another movable component; on fig.Z - the work of two shoulders lever.

A frame with a fixed optical component I is installed in a housing (not shown), on which coaxially and rigidly jointed spindle screws 2 and 3 with a metric thread are fixed on bearings 1

different pitch and direction of cutting and copier 4. Rotation on screws 2 and 3 is transmitted through a gear wheel 5 from an electric drive (not shown). One of the screws has the right direction of the thread, the other - the left. The screw 3 moves the nut 6, with which the frame 7 is directly connected to the movable optical component II via the bracket 7. At the same time, the bracket 7 prevents the rotation of the nut 6 around the axis of the screw 3 during its rotation. The screw 2 moves the nut 8, on which the double-arm lever 9 is attached. The lever roller 10 rests on the copier 4. The frame with the movable optical component II is connected to the roller 11 of the second arm 9 through the bracket 12, which at the same time prevents the nut 8 from turning around the axis. Springs 13 and 14 oboscheO

VI th

ate

CJ

One of the possible methods of force locking mechanism is used.

Figure 2 shows the dependence of the movement of component III on the movement of component II (curve I). The movement of component III is decomposed into two components — linear (straight) and non-linear, which is defined as the difference of the ordinates of points, for example, M and N, having a common abscissa. The angle of inclination of the straight line 12 (Fig. 3), and hence the maximum amplitude of the nonlinear component, is determined by the ratio of the thread pitch of the screws 2 and 3. The non-linear component is set by copier 4, shifted by the value A of roller 10 (Fig. 3) . As a result, the lever 9 is turned and the roller 11 is displaced by the value L x, in case the arms of the lever are equal and the angle between them is straight Ax Ah Ay.

Thus, the optical component I moves linearly, and the movement of the optical component III is the sum of the linear movement of the nut 8 and the additional displacement of the frame relative to the nut 8 due to the reversal of the lever 9 defined by the profile of the copier 4.

One of the known methods is used to compensate for the gaps in the screw pairs.

The device works as follows.

When the gear 5 and the screws 2 and 3 are rotated together, the nut 6, together with the component And and the nut 8, move towards A FRIEND to a Friend. In this case, the roller 10 rolls around the copier 4, as a result of which the lever 9 rotates relative to its initial position by a certain angle and the roller 11, overcoming the force of the spring 13, displaces the mandrel of the HI component relative to the nut 8.

The proposed mechanism for changing the focal distance of a pancritical lens provides an implementation of optical schemes in which the moving optical components must move both in one direction and towards each other, and the movement of one of them may be several times smaller than the other.

In the case of moving the movable components in one direction, both screws are made with right or left thread. Making precise lead screws with metric threads does not cause any particular difficulties. The profile of the copier depends on

the ratios of the thread of the screws, the sizes of the arms of the lever and their ratios among themselves, as well as their initial position. This allows you to get a whole range of

Copier profiles with the same law of moving components and choosing the best one.

In comparison with the known device, the proposed mechanism for changing the focal distance of a pancratic object has a lower manufacturing labor intensity.

Simplification of the mechanism for modifying the cam mechanism also improves the quality of the image given by the system, the errors of which arise due to the inevitable errors in the manufacture (in the prototype) of the cam grooves and backlashes in conjunction with the lead with the groove,

Compared with the known device, in which the kinematic closure of the driver and the spatial cam is made by means of a probe (finger), the proposed mechanism for changing the focal distance makes contact in the screw-nut area over the surface, which ensures a higher resistance to wear and tear. vibrations and shock loads.

Claims (1)

Invention Formula The mechanism for changing the focal distance of a pancritical lens containing frames with optical components, one of which is fixed, the second is mounted for movement in two guides along the optical axis, and a third is arranged for joint movement with the second component B in the opposite direction to it, two coaxial, rigidly articulated driving screws associated with the corresponding components using rods, characterized in that in order to simplify manufacturing while increasing 5 image quality of the lens, two rigidly interconnected lead screws are made with threads of different pitch and different thread directions, and a flat-head copier and double-sided lever are additionally introduced into the mechanism, the second component is connected with a nut mounted on the same lead screw, and the third the component is connected to the nut mounted on the second drive screw with the help of it fixed to it 5 levers of the lever and simultaneously with a flat cam over the second lever lever. CL five Fi.Z