Nested disc cam focusing mechanism

Abstract

The invention discloses a nested disc cam focusing mechanism, belonging to the field of cam focusing. The nested disc cam focusing mechanism provided by the invention solves the problems that a focusing mechanism of a nested optical system is complicated, the focusing precision is low and the like. The mechanism mainly comprises a first microscope base, a second microscope base, a third microscope base, a fourth microscope base, a fifth microscope base, a sixth microscope base, a slider, a guide rail, disc cams, a driven member, a spring and the like, wherein the first microscope base and the sixth microscope base form a first microscope base group; the second microscope base and the fifth microscope base form a second microscope base group; the third microscope base and the fourth microscope base form a third microscope base group; the microscope base groups move relatively along the direction of an optical axis to form a nested structure; three disc cams control the moving rules of the three groups of nested microscope bases through the driven member respectively and change the positions of the three groups of nested microscope bases so as to realize focusing of the whole system; and moreover, due to the independent microscope base and disc cam structure, compared with a cylindrical cam, the structure is simple, the processing cost is low, and the focusing precision is high.

Description

technical field [0001] The invention belongs to the field of cam focusing. Background technique [0002] Usually, the lens is circular, and the corresponding lens holder or lens barrel used to assemble and fix the lens is also circular. In order to make the structure simple and compact, easy to process, and to ensure the coaxiality between lenses and various matching tolerances, cylindrical cams are mostly used in the field of cam focusing. However, in some optical focusing systems, the use of cylindrical cam structures has its limitations. [0003] Such as figure 1 In the shown optical system, lenses a and f constitute the first lens group, lenses b and e constitute the second lens group, and lenses c and d constitute the third lens group. When focusing, the first and third lens groups move to the left, the second lens group moves to the right, and the six lenses form a triple nested structure. for something like figure 1 As shown in the nested optical system, it will ...

AI Technical Summary

Problems solved by technology

As the number of nesting layers increases, the number of nesting layers of the lens barrel or lens base will increase exponentially, and there will be processing and assembly errors in each nesting layer. If this continues, the error will become larger and larger until it cannot be achieved. Meet the accuracy requirements of the system

Moreover, as the number of nesting layers increases, the number of cam grooves required will also increase accordingly. If all the cam grooves are processed on the same lens barrel, there may be a phenomenon that the cam grooves cross, making it impossible to achieve Accurate focusing of individual nested layers

[0004] Furthermore, in order to allow the roller or follower to rotate flexibly in the cam groove, the width of the cam groove should be slightly larger than the diameter of the roller, which will cause a gap between the cam groove and the roller, which will affect the focusing accuracy

Although there are currently some measures that can theoretically eliminate the gap between the cam groove and the roller, this will undoubtedly increase the overall complexity of the mechanism, increase the processing cost and the difficulty of assembly and adjustment

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