Devices, Systems And Methods For Three-Dimensional Printing

What is this patent about?

’489 is related to the field of additive manufacturing, specifically three-dimensional (3D) printing. Traditional 3D printing methods often rely on infrared (IR) lasers, which can be limited in resolution, speed, and surface finish. The patent addresses the need for improved 3D printing systems that can overcome these limitations, particularly for manufacturing parts with submicron resolution, low surface roughness, and high build rates.

The underlying idea behind ’489 is to use a high-power, high-brightness visible laser source in a 3D printing system. This is achieved by scaling visible laser diodes using stimulated Raman scattering (SRS) to generate a coherent beam of visible light. The shorter wavelength of visible light allows for a smaller spot size and improved material absorption, leading to higher resolution, faster processing speeds, and better surface quality compared to IR laser-based systems.

The claims of ’489 focus on a 3D printing system comprising a laser light source that generates a coherent beam of visible light (wavelength between 400 nm and 750 nm, power of at least 100W), an area for holding a metallic solid substrate, a scanning module to direct the beam according to a predetermined pattern, and a computer control system. The system is configured to use the coherent beam to melt or soften the metallic substrate to form a part. Some claims specify the use of a plurality of laser diodes interfaced to provide the coherent beam, or the use of blue light (wavelength not specified) with a power of at least 500W.

In practice, the system uses an array of visible laser diodes whose outputs are combined and shaped to match the requirements of a Raman convertor fiber. This fiber uses stimulated Raman scattering to convert the combined laser diode output into a single, coherent laser beam. The beam is then directed by a scanning module (e.g., galvanometers or linear translation stages) and focused onto a substrate (e.g., powder bed) to selectively melt or fuse the material, building the 3D object layer by layer.

The use of visible lasers, particularly blue lasers, offers several advantages over traditional IR lasers. The shorter wavelength allows for a smaller focused spot size, leading to higher resolution. Furthermore, many materials exhibit higher absorption at visible wavelengths, resulting in faster processing speeds. The patent also highlights the use of low-loss optical fibers to minimize Rayleigh scattering, enabling efficient SRS and high-power laser operation. By using a modular laser plate design , the system can be scaled to achieve high power levels while maintaining beam quality.