Selectively melt micron-sized particles using micro-mirrors

A three-dimensional (3D) printing system comprising:

• a spreader to spread a layer of powder on a printing platform, the powder having micron-sized particles;
• a chip containing an array of movable micro-mirrors;
• a controller to control each of the movable micro-mirrors to be in one of a first position or a second position;
• and
• a light source to direct a pulse of light onto the array of micro-mirrors, wherein each of the micro-mirrors that is in the first position reflects light onto a respective area on the layer of micron-sized particles with sufficient intensity to at least partially melt the micron-sized particles in the respective area and each of the micro-mirrors that is in the second position reflects light away from the layer of powder.

A method comprising:

• determining areas to be fused together on a layer of micron-sized particles, wherein each of the areas is to be illuminated by a respective micro-mirror in an array of micro-mirrors;
• setting each of the micro-mirrors that are to illuminate the determined areas to an active position;
• setting each of the micro-mirrors that are not to illuminate the determined areas to an inactive position;
• and
• activating a light source to pulse a beam of light onto the array of micro-mirrors, wherein the micro-mirrors that are set to the active position direct the light to the determined areas with sufficient intensity to at least partially melt the micron-sized particles onto which the light is directed.