Microlens array acquiring adjustable double focuses

Abstract

The invention discloses a microlens array acquiring adjustable double focuses. The microlens array is a column surface type lens array and is novel in structure design. The long focal depth characteristic is realized based on the microlens array; focused spots can change from a single focus to double focuses and a distance between the double focuses is adjustable with use of a focusing mirror andby rotating in a column surface cross line direction of the microlens array based on a micro-surface spectroscopic characteristic, and the focal depth of a focused beam of the double focuses is increased greatly. The microlens array acquiring the adjustable double focuses is applied to laser welding, can especially help to reduce lapping width of boards and lower clamping requirements of boards, reduces various defects of highly reflective boards in welding, improves welding seam quality and lengthens welding depth.

Description

technical field [0001] The invention relates to the technical field of laser welding, in particular to a microlens array for obtaining adjustable bifocals. Background technique [0002] Laser processing technology covers various laser processing technologies such as laser cutting, welding, quenching, drilling, micromachining, etc., and utilizes the basic characteristics of the interaction between laser and matter. Because the laser beam has the advantages of non-contact with the processing material, fast processing speed and excellent quality, it has established that the laser processing technology is an irreplaceable high-tech. [0003] Laser welding has the advantages of high energy density, fast speed, small welding deformation, narrow melting width and heat-affected zone. However, for laser welding of high-reflection materials, ordinary welding methods are not enough to meet the welding requirements, such as laser welding of aluminum alloys, which are prone to laser wel...

AI Technical Summary

Problems solved by technology

The beam-splitting prism is used to split the light, and the focal distance of the single lens cannot be adjusted. When the double lens achieves a single focus, the out-of-focus beam segments do not overlap, resulting in a larger divergence angle. When achieving a double focus, the shape of the defocus spot is asymmetrically distributed; Bifocal adjustment cannot be realized; the free-form surface lens group realizes bifocal, and two lenses need to be combined and moved in coordination to realize bifocal and energy ratio adjustment. Spherical lenses cannot withstand high-power applications, and similar to double-piece beam-splitting prisms, the shape of the defocused spot is asymmetrically distributed under dual focus, which is not conducive to laser welding

Images