Abstract: An apparatus and method for fabricating a three dimensional model from a composite model formed or a plurality of successive layers of model material and sacrificial mold material. Each successive layer is constructed by depositing, drop-by-drop, at least one line of sacrifical mold material delineating at least one boundary of the model material within the layer and thereafter depositing the model material onto all delineated regions of the layer by spray deposition. Each successive layer is completed by a planing process which removes the undesired thickness of both the sacrificial and the model materials. Following completion of the composite model, the sacrificial mold material is removable from the composite model, by a process effecting only the sacrificial mold material, to produce the three dimensional model. A device, for depositing the model material at the rate faster than the rate that the mold material is deposited, is also described.

Abstract: A dual drum rotary image scanner has a headstock and a tailstock between which may be mounted drums of different diameter. The tailstock has substantially annular surfaces which contact corresponding surfaces on the different diameter drums. The different drums, when held in the scanner, each create a different separation between the headstock and tailstock. These different separations are detected by photodetectors, the outputs of which are received by a system controller. The controller uses the photodetector signals to control motors that position the scanning head and the transmittance illuminator relative to the surface of the particular drum mounted in the scanner. The motors turn pinions which, in turn, move racks to which are attached the scanning head and the transmittance illuminator, respectively. The movement of the scanning head also results in the modification of the optical path within the optics box of the scanner.

Abstract: An ink jet printer with a continuous supply of sheet material from a spool contained within an imaging drum. The sheet material is withdrawn from the interior of the drum by a pair of rollers carried by the drum and removably connected to an external drive system. The sheet material travels around the drum and is held by the rollers in that position. The external drive system is then disconnected allowing the drum to rotate while a printing head scans the surface of the sheet material to produce the desired image. After the imaging process, the drum is stopped in a predetermined position and the rollers connected to the external drive. The rollers are then driven to eject the imaged sheet material while a fresh supply is withdrawn from the interior of the drum and wrapped around its outer surface.

Abstract: An ink jet printer in which a roll of paper is stored within an imaging drum and feeds through a longitudinal opening in the drum to the outside, passes around the drum, where it is held in place during the imaging process, and then ejected from the drum and cut off. While the imaged sheet is being ejected from the drum, the next length of paper is drawn from the interior of the drum and around the outside of the drum in position for the next imaging operation. The paper is withdrawn from the drum by a traction roller that engages only the center portion of the paper to prevent the paper from skewing because of unequal forces applied to the edge portions of the paper. The same traction roller is also used in a reverse mode to tension the paper around the drum.

Abstract: An ink jet printer having an imaging drum with a supply of paper within the drum. The paper is transported by rollers mounted on the imaging drum that are controlled by the transverse position of a cutter mechanism that cuts off the imaged paper. The paper passes from the supply spool in the imaging drum through a longitudinal slot in the drum to the outside, around the exterior of the drum, where it is held in place during the imaging process, and then ejected from the drum to the desired length and cut off. While the imaged sheet is being ejected from the drum, the next length of paper is drawn from the drum and around the outside of the drum in position for the next imaging operation. The length of paper that remains projecting from the drum after the imaged paper has been cut off is then withdrawn into the interior of the drum through the longitudinal opening in the drum surface until only a short stub, which will not interfere with the subsequent imaging operation, remains protruding from the drum.