Zooming telecentric lens

Abstract

The invention discloses a zooming telecentric lens and relates to optical techniques. The zooming telecentric lens sequentially comprises a first lens group with positive refraction index focal power, a second lens group with positive refraction index focal power, a third lens group with negative refraction index focal power, a fourth lens group with positive refraction index focal power and a fifth lens group with positive refraction index focal power from an object plane to an image plane; the first lens group, the third lens group and the fifth lens group are fixed groups, and the second lens group and the fourth group are moving groups; when the zooming telecentric lens zooms from low power to high power, the second lens group is close to the first lens group, and the fourth lens group is close to the third lens group; during zooming, the spot position is adjusted and changed independently. The zooming telecentric lens is high in zoom ratio, and object space resolution can reach up to 4.7 micrometers; conjugate distance is kept unchanged during zooming, zooming positions adopt telecentric object space design, and accuracy of measured data and repeatability of the measured data at different depth-of-field locations are guaranteed; distortion of TV is less than 0.05%.

Description

technical field [0001] The invention relates to optical technology, in particular to a variable magnification telecentric lens, the conjugate distance of which is fixed and the object space is telecentric, and is suitable for precise image measurement. Background technique [0002] Optical imaging lenses are widely used in precision manufacturing fields such as electronics to detect product quality. As the quality requirements of the precision manufacturing industry are getting higher and higher, the precision testing industry presents the following trends: 1. Product testing has shifted from random inspection to full inspection; 2. Off-line inspection has shifted to online inspection; 3. Inspection accuracy has shifted from 0.01mm level to micron level; 4. Semi-automatic measurement turns to one-button automatic measurement. This requires that the testing equipment used must have high efficiency, high accuracy, and convenient operation, which inevitably requires extremely ...

AI Technical Summary

Problems solved by technology

[0007] The technical problem to be solved in the present invention is to overcome the shortcomings of the existing fixed magnification telecentric lens that the magnification cannot be changed, the detection field of view of the continuous variable magnification lens is small, and the magnification change of the telecentric lens combined with several magnifications is very limited. telecentric lens

The lens: 1. The conjugate distance is fixed, and the working distance does not change due to the change of the multiple; 2. The object telecentric design fundamentally solves the problem of measurement deviation within the depth of field; 3. Realizes continuous zooming , the user can freely choose the most suitable multiple between the maximum and minimum multiples when using it, and at the same time meet the most suitable detection field of view

Images