Spherometer with adjustable measuring diameter, and measuring method for radius of curvature and offset

Abstract

The invention discloses a spherometer with an adjustable measuring diameter, and a measuring method for radius of curvature and offset. The spherometer comprises an indicating gauge and a fixed base for mounting the indicating gauge, wherein the fixed base is provided with at least three vertical guide rails peripherally by regarding the center of a through hole as the center, the spherometer further comprises a lifting platform capable of sliding up and down relative to the vertical rails, the fixed base is provided with a plurality of base chutes spaced apart from the vertical guide rails peripherally by regarding the center of the through hole as the center, and the base chutes are provided with sliders capable of sliding on the base chutes. The three sliders are driven by the lifting platform to move closer to or away from the center so as to realize the measurement of workpieces of different diameters without replacing the measuring ring, and the whole device takes up small spaceand is simple and convenient. Three legs simultaneously move in the diameter direction to perform a centering function, so that the measuring head of the indicating gauge is aligned with the center ofsphere of the workpieces, and the measurement is more accurate. A locking mechanism can be used to lock at a specified position at any time, and the operation is simple and convenient.

Description

technical field [0001] The invention relates to the technical field of measuring spherical and aspheric optical elements, in particular to a spherometer with adjustable measuring diameter and a method for measuring curvature radius and offset. Background technique [0002] Spherical and aspherical mirrors are widely used in modern defense and commercial fields, and their sizes range from tens of millimeters to thousands of millimeters. Large spherical mirrors, such as those over 500mm, have other measurement methods because of their large size. For the measurement of small and medium-sized spherical mirrors and aspheric mirrors, the spherometer can be used to directly measure in-situ, avoiding the time-consuming disadvantages of workpiece clamping. A spherometer is an instrument used to measure the radius of curvature of a spherical or aspheric optical element. As a precision element, if the measurement is inaccurate, it will cause great errors in the focus and subsequent pr...

AI Technical Summary

Problems solved by technology

[0004] 1. The synchronization performance is not good when the chuck rotates, which makes it impossible to accurately determine the center of the circle

[0005] 2. The spherometer is hand-held. Due to the weight of the workpiece, it can only measure small workpieces.

[0006] 3. The use of spiral micrometer for measurement will affect the accuracy of measurement

[0007] The second type is a spherometer using a measuring ring. This kind of spherometer can achieve high precision, but one kind of measuring ring cannot measure workpieces with different diameters, and the applicable range is poor. It is necessary to prepare multiple measuring rings with different measuring ranges. ring, and it is troublesome to replace the measuring ring

[0009] 1. Using the grating ruler to measure and then calculate, the theoretical error will accumulate, and the installation is more cumbersome

[0010] 2. The spherometer is controlled by a computer and a stepping motor, so it is expensive and takes up a lot of space, which is not easy to use

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