Rapid prototyping apparatus

Abstract

Apparatus for producing an object by sequentially forming thin layers of a construction material one on top of the other responsive to data defining the object, the apparatus comprising: a plurality of printing heads each having a surface formed with a plurality of output orifices and controllable to dispense the construction material through each orifice independently of the other orifices; a shuttle to which the printing heads are mounted; a support surface; and a controller adapted to control the shuttle to move back and forth over the support surface and as the shuttle moves to control the printing heads to dispense the construction material through each of their respective orifices responsive to the data to form a first layer on the support surface and thereafter, sequentially the other layers; wherein each printing head is dismountable from the shuttle and replaceable independently of the other printing heads.

1 - 59 . (canceled) 
   
   
       60 . Apparatus for producing an object by sequentially forming thin layers of a construction material one on top of the other responsive to data defining the object, the apparatus comprising:
 a movable set comprising multiple printing heads, each having a surface formed with a plurality of output orifices offset from each other in a first direction by a first distance, the plurality of printing heads of the set being placed in order in a second, scan, direction substantially perpendicular to the first direction; and   a controller adapted to scan the movable set with respect to a support surface in the second, scan, direction and to control the printing heads to dispense the construction material through each of their respective orifices responsive to the data, such that each orifice dispenses material along a construction line separated by said first distance from the line along which a neighboring orifice in a same head dispenses its material,   wherein the each of the heads that deposits construction material after the first head, deposits construction material along lines between the lines along which construction material was previously deposited by the other printer heads.   
   
   
       61 . Apparatus according to  claim 60  wherein each of the heads that deposits construction material after the first head, deposits construction material along lines equidistant from adjacent lines along which construction material was previously deposited by the other printer heads. 
   
   
       62 . Apparatus according to  claim 60  wherein the set of printer heads comprises
 a movable set of four printing heads, first, second, third and fourth printing heads of the set being placed in that order in the second, scan, direction,   wherein the orifices in the second printing head are offset from those in the in the first printing head, in the first direction, by one half the first distance, such that they dispense the construction material along lines substantially equidistant from lines along which construction material is dispensed by the first printing head; and   wherein the orifices in the third and fourth printing heads are so positioned that they dispense construction material along lines equidistant from the adjacent lines along which material is dispensed by the first and second heads.   
   
   
       63 . Apparatus according to  claim 62  wherein the construction material is deposited in a first layer in accordance with the data in a first pixel matrix having a pitch, and in a second layer above the first layer, responsive to the data in a second pixel matrix,
 wherein the first and second pixel matrices are offset from each other in one or both of the first and second directions by an amount that is less than the pitch.   
   
   
       64 . Apparatus for producing an object by sequentially forming thin layers of a construction material one on top of the other responsive to data defining the object, the apparatus comprising:
 at least one printing head, having a surface formed with a plurality of output orifices offset from each other in a first direction by a first distance; and   a controller adapted to scan the at least one printing head with respect to a support surface in the second, scan, direction perpendicular to the first direction and to control the printing heads to dispense the construction material through each of their respective orifices responsive to the data, such that each orifice dispenses material in accordance with a first pixel matrix having a pitch to form a first layer of patterned construction material; and then to scan the at least one printing head with respect to the support surface in the scan direction to form a second layer above the first layer, responsive to the data in a second pixel matrix,   wherein the first and second pixel matrices are offset from each other in one or both of the first and second directions by an amount that is less than the pitch.   
   
   
       65 . Apparatus according to  claim 64  wherein, while forming the second layer, the at least one printing head is shifted in first direction by a whole number of pitches plus said offset from its position in forming the first layer 
   
   
       66 . Apparatus according to  claim 64  wherein the offset is one half the pitch. 
   
   
       67 . Apparatus according to  claim 64  wherein the first and second pixel matrices are offset from each other in the second direction. 
   
   
       68 . Apparatus according to  claim 60  wherein the printing heads are mounted in a shuttle and wherein each printing head comprises at least one registration structure that matches a registration structure comprised in the shuttle and when a printing head is mounted to the shuttle its at least one registration structure contacts the corresponding shuttle registration structure and positions the printing head accurately in the shuttle. 
   
   
       69 . Apparatus according to  claim 68  wherein the at least one registration structure comprised in each printing head and its corresponding shuttle registration structure position the printing heads so that their respective lines of orifices are parallel. 
   
   
       70 . Apparatus according to  claim 68  wherein the at least one registration structure comprised in each printing head and its corresponding shuttle registration structure, position the printing heads so that the first orifice in each printing head is accurately positioned relative to the first orifices of the other printing heads. 
   
   
       71 . Apparatus according to  claim 60  wherein the construction material comprises a photopolymer. 
   
   
       72 . Apparatus according to  claim 71  and comprising a lamp that provides radiation to polymerize the photopolymer. 
   
   
       73 . Apparatus for producing an object by sequentially forming thin layers of a material one on top of the other responsive to data defining the object, the apparatus comprising:
 at least one printing head having a surface formed with at least one output orifice and controllable to dispense a photopolymer material in liquid form through the orifice;   a wiper; and   a controller adapted to control the printing head to dispense the photopolymer and sequentially form the layers, and to move the printing head over the wiper to clean the surface in which the orifices are formed,   wherein the cleaning blade is formed with at least one slot that partitions the cleaning blade into a plurality of teeth each having an edge that contacts an orifice surface of a different one of the plurality of printing heads and scrapes excess construction material form the surface.   
   
   
       74 . Apparatus according to  claim 73  wherein the wiper comprises at least one cleaning blade having an edge that scrapes excess construction material from the surface when the controller controls the surface to move over the wiper. 
   
   
       75 . Apparatus according to  claim 73  wherein the cleaning blade is formed from a resilient material so that the edge that contacts the surfaces resiliently contacts the surface. 
   
   
       76 . Apparatus according to  claim 75  wherein the edge is scalloped and has a different scallop corresponding to each printing head of the at least one printing head. 
   
   
       77 . Apparatus according to  claim 73  wherein the at least one cleaning blade comprises at least two cleaning blades. 
   
   
       78 . Apparatus according to  claim 77  wherein a cleaning blade of the at least two cleaning blades has an edge that does not contact the orifice surface of a printing head but moves along and in close proximity to the surface when the controller controls the surface to move over the wiper. 
   
   
       79 . Apparatus according to  claim 60  and comprising an obstacle detection system that detects defects in a layer that protrudes from a surface of the layer. 
   
   
       80 . Apparatus according to  claim 79  wherein the obstacle detection system comprises:
 a laser that provides a laser beam that contacts or is located close to the surface of the layer along a length of the laser beam;   a detector that receives light from the laser beam; and   wherein light that the detector receives from the laser is at least partially blocked by a defect that protrudes from the surface.   
   
   
       81 . Apparatus according to  claim 65  wherein the offset is one half the pitch. 
   
   
       82 . Apparatus according to  claim 64  wherein the printing heads are mounted in a shuttle and wherein each printing head comprises at least one registration structure that matches a registration structure comprised in the shuttle and when a printing head is mounted to the shuttle its at least one registration structure contacts the corresponding shuttle registration structure and positions the printing head accurately in the shuttle. 
   
   
       83 . Apparatus according to  claim 82  wherein the at least one registration structure comprised in each printing head and its corresponding shuttle registration structure position the printing heads so that their respective lines of orifices are parallel. 
   
   
       84 . Apparatus according to  claim 82  wherein the at least one registration structure comprised in each printing head and its corresponding shuttle registration structure, position the printing heads so that the first orifice in each printing head is accurately positioned relative to the first orifices of the other printing heads. 
   
   
       85 . Apparatus according to  claim 64  wherein the construction material comprises a photopolymer. 
   
   
       86 . Apparatus according to  claim 85  and comprising a lamp that provides radiation to polymerize the photopolymer. 
   
   
       87 . Apparatus according to  claim 64  and comprising an obstacle detection system that detects defects in a layer that protrudes from a surface of the layer. 
   
   
       88 . Apparatus according to  claim 73  and comprising an obstacle detection system that detects defects in a layer that protrudes from a surface of the layer. 
   
   
       89 . Apparatus according to  claim 87  wherein the obstacle detection system comprises:
 a laser that provides a laser beam that contacts or is located close to the surface of the layer along a length of the laser beam;   a detector that receives light from the laser beam; and   wherein light that the detector receives from the laser is at least partially blocked by a defect that protrudes from the surface.   
   
   
       90 . Apparatus according to  claim 88  wherein the obstacle detection system comprises:
 a laser that provides a laser beam that contacts or is located close to the surface of the layer along a length of the laser beam;   a detector that receives light from the laser beam; and   wherein light that the detector receives from the laser is at least partially blocked by a defect that protrudes from the surface.