| abstract |
A method and apparatus for selectively depositing a layer of material from a gas phase to produce a part comprising a plurality of deposited layers. The apparatus includes a computer controlling a directed energy beam, such as a laser, to direct the laser energy into a chamber substantially containing the gas phase to preferably produce photodecomposition or thermal decomposition of the gas phase and selectively deposit material within the boundaries of the desired cross-sectional regions of the part. For each cross section, the aim of the laser beam is scanned over a target area and the beam is switched on to deposit material within the boundaries of the cross-section. Each subsequent layer is joined to the immediately preceding layer to produce a part comprising a plurality of joined layers. In an alternate embodiment of the present invention, a gas phase is condensed on a surface and a laser beam is used to selectively evaporate, transform, activate or decompose material in each layer. The apparatus of the present invention preferably comprises a computer controlled laser generating and scanning system for selectively depositing or evaporating material to produce a part. The present invention further comtemplates an n-degree of freedom positioning apparatus for positioning a target outer layer and a detecting apparatus which can non-intrusively detect the position and thickness of the deposited layer, both of which are close looped into a computer to produce the desired part. |