Surface resolution in three-dimensional objects by inclusion of thin fill layers
First Claim
1. An improved stereolithographic method for forming a three-dimensional object on substantially a layer by layer basis from a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of forming successive layers of unsolidified material of desired thickness in preparation of forming layers of structure of said three-dimensional object and exposing said layers of unsolidified material to synergistic stimulation to form said layers of structure of said three-dimensional object, including forming a last layer of unsolidified material and exposing said last layer to synergistic stimulation to form a last layer of structure thereby completing formation of all layers of said three-dimensional object, the improvement comprising the step of:
- reducing at least part of an up-facing surface discontinuity between two layers by selectively exposing said unsolidified building material within at least part of said discontinuity to synergistic stimulation wherein the synergistic stimulation impinges on a surface of said material with an orientation close to perpendicular prior to exposing said last layer of structure of said three-dimensional object.
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Accused Products
Abstract
Methods and apparatus for reducing surface discontinuities, resulting from the formation of a three-dimensional object out of a plurality of stacked layers, during layer by layer stereolithographic formation of the three-dimensional object. The discontinuities between layers are reduced by utilizing formation and solidification of thin fill layers near the edges of thicker structural layers or by utilizing surface tension effects to smooth discontinuities between the structural layers by formation of meniscuses of building material and solidifying the meniscuses.
124 Citations
69 Claims
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1. An improved stereolithographic method for forming a three-dimensional object on substantially a layer by layer basis from a material capable of selective physical transformation upon exposure to synergistic stimulation comprising the steps of forming successive layers of unsolidified material of desired thickness in preparation of forming layers of structure of said three-dimensional object and exposing said layers of unsolidified material to synergistic stimulation to form said layers of structure of said three-dimensional object, including forming a last layer of unsolidified material and exposing said last layer to synergistic stimulation to form a last layer of structure thereby completing formation of all layers of said three-dimensional object, the improvement comprising the step of:
reducing at least part of an up-facing surface discontinuity between two layers by selectively exposing said unsolidified building material within at least part of said discontinuity to synergistic stimulation wherein the synergistic stimulation impinges on a surface of said material with an orientation close to perpendicular prior to exposing said last layer of structure of said three-dimensional object. - View Dependent Claims (52, 53, 54)
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2. An improved stereolithographic method for forming a three-dimensional object on substantially a layer by layer basis from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of forming successive layers of unsolidified material of desired thickness in preparation for forming layers of structure of said three-dimensional object and exposing said layers of unsolidified material to synergistic stimulation to form said layers of structure of said three-dimensional object, including forming a last layer of unsolidified material and exposing said last layer to synergistic stimulation to form a last layer of structure thereby completing formation of all layers of structure of said three-dimensional object, the improvement comprising the step of:
reducing at least part of a down-facing surface discontinuity between a first and a second layer by selectively exposing said unsolidified material within at least part of said discontinuity to synergistic stimulation prior to exposing said last layer of structure of said three-dimensional object but after a layer of material is formed in preparation for formation of said second layer of structure. - View Dependent Claims (55)
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3. An improved stereolithographic method for forming a three-dimensional object, having an exterior surface, on substantially a layer by layer basis from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of forming successive layers of unsolidified material of desired thickness in preparation for forming layers of structure of said three-dimensional object and exposing said layers of unsolidified material to synergistic stimulation to form said layers of structure of said three-dimensional object, including forming a last layer of unsolidified material and exposing said last layer to synergistic stimulation to form a last layer of structure thereby completing formation of all layers of said three-dimensional object, the improvement comprising the steps of:
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selectively curing a layer of material of desired thickness to form at least a portion of an internal region of a layer of structure, said layer of structure having a z-range corresponding to said desired thickness; and forming at least a portion of said exterior surface of said three-dimensional object from at least one fill layer which has a thicknesses less than said desired thickness, and wherein said at least portion of said exterior surface corresponds to said z-range, and wherein said at least one fill layer is formed prior to formation of said last layer of structure of said three-dimensional object. - View Dependent Claims (56)
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4. A method for reducing a surface discontinuity between first and second structural layers of a three-dimensional object being stereolithographically formed, said discontinuity comprising a deviation between a down-facing region of a three-dimensional object surface and a desired object envelope, the down-facing region to comprise an end of a not yet formed first structural layer which is to contact at least in part the object envelope, and an extension region which is to comprise a portion of a lower surface of a not yet formed second structural layer which extends beyond the end of the first structural layer, and which is to contact, at least in part, the object envelope, the lower surface to contact at least in part an upper surface of the first structural layer, the method comprising the steps of:
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containing a volume of flowable material, which material is capable of selective physical transformation upon exposure to synergistic stimulation, whereupon a working surface of the material is formed; selectively exposing material at said working surface to a first exposure of said synergistic stimulation to form said first structural layer having a first cure depth; selectively exposing material at the working surface to a second exposure of the synergistic stimulation to form a first fill layer, said fill layer being cured to a depth less than said first cure depth, said fill layer also having a first edge and a second edge and having an upper surface; forming an untransformed layer of said material over at least a portion of said upper surface of said first structural layer, whereupon an upper surface of said untransformed layer defines, at least in part, a new working surface; and selectively exposing material at the new working surface to a third exposure of the synergistic stimulation to form said second structural layer, wherein said lower surface of said second structural layer contacts at least in part said upper surface of said first fill layer. - View Dependent Claims (5, 6, 7, 8)
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9. A method for reducing a surface discontinuity between first and second structural layers of a three-dimensional object being stereolithographically formed from a flowable material capable of selective physical transformation upon exposure to synergistic stimulation, said discontinuity comprising a deviation between a down-facing region of said three-dimensional object surface and a desired object envelope, the down-facing region comprising an end of an already-formed first structural layer which contacts at least in part the envelope, and an extension region comprising a portion of a lower surface of a not yet formed second structural layer, the lower surface of said second structural layer, after formation, contacting at least in part an upper surface of the first structural layer, and the second structural layer having an end which extends beyond the end of the first structural layer by the extension region, which end contacts at least in part the object envelope, wherein the first and second structural layers have thicknesses, the method comprising:
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coating over at least a portion of said first structural layer with a layer of desired thickness of said flowable building material in preparation for formation of said second structural layer; selectively exposing said coating of flowable building material to synergistic stimulation to form at least a portion of said second structural layer; and selectively exposing, at least in part, the extension region of the second structural layer to synergistic stimulation to expose material situated below the extension region of the second structural layer to form a first fill layer. - View Dependent Claims (10, 11, 12, 13)
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14. A method for reducing a surface discontinuity between first and second structural layers of a three-dimensional object being stereolithographically formed from a flowable material capable of selective physical transformation upon exposure to synergistic stimulation, said discontinuity comprising a deviation between an up-facing region of a three-dimensional object surface and a desired object envelope, the up-facing region comprising an end of an already-formed first structural layer, and an extension region comprising at least part of an upper surface of an already-formed second structural layer, the first structural layer having a lower surface which contacts at least in part the upper surface of the second structural layer, and the second structural layer having an end which extends beyond the end of the first structural layer by the extension region, which end contacts at least in part the envelope, wherein the first and second structural layers have thicknesses, the method comprising:
selectively exposing said material to synergistic stimulation to form a first fill layer having a thickness less than the thickness of the first structural layer. - View Dependent Claims (15, 16, 17, 18, 19)
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20. A method for reducing a surface discontinuity between first and second structural layers of a three-dimensional object being stereolithographically formed from a flowable material capable of selective physical transformation upon exposure to synergistic stimulation, said discontinuity comprising a deviation between an up-facing region of a three-dimensional object surface and a desired object envelope, the up-facing region to comprise an end of a not yet formed first structural layer, an extension region comprising at least a portion of an upper surface of an already-formed second structural layer, the second structural layer having an end which is to extend beyond the end of the first structural layer by the extension region, and which ends contacts at least in part the envelope, wherein the second structural layer has an upper surface which is to contact, at least in part, a lower surface of the first structural layer, the second structural layer having an upper surface situated at about a working surface of said flowable material, the method comprising:
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forming a first layer of said flowable material over at least part of said extension region in preparation for forming a first fill layer; and selectively exposing said first layer of said material to synergistic stimulation to form a first fill layer having a lower surface which contacts, at least in part, the extension region of the second structural layer. - View Dependent Claims (21, 22, 23, 24)
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25. A method for reducing a surface discontinuity between first and second structural layers of a three-dimensional object being stereolithographically formed, said discontinuity comprising a deviation between a region of a three-dimensional object surface and a desired object envelope, the region to comprise an end of a not yet formed first structural layer, and an extension region, the extension region to comprise at least a portion of a surface of a not yet formed second structural layer, the second structural layer to have an end which is to extend beyond an end of the first structural layer by the extension region, the ends to contact at least in part the envelope, the surface of the first structural layer to contact, at least in part, a surface of the first structural layer, and the first and second structural layers to have thicknesses, the method comprising the following steps:
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containing a volume of flowable material, the material capable of selective physical transformation upon exposure to synergistic stimulation; selectively exposing said material to a first exposure to said synergistic stimulation to form a first selected one of said first and second structural layers; selectively exposing said material to a second exposure of said synergistic stimulation to form a first fill layer having a first portion which contacts, at least in part, a portion of said first selected one; and selectively exposing said material to a third exposure to said synergistic stimulation, to form a second selected one of said first and second structural layers which is different from said first selected one, wherein a time order of exposure is one of the first exposure followed by the second exposure followed by the third exposure or the first exposure followed by the third exposure followed by the second exposure. - View Dependent Claims (26, 27)
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28. A method for reducing a surface discontinuity between first and second structural layers of a three-dimensional object being stereolithographically formed from a flowable material capable of selective physical transformation upon exposure to synergistic stimulation, said discontinuity comprising a deviation between a region of a three-dimensional object surface and a desired object envelope, the region to comprise an end of a not yet formed first structural layer, and an extension region, the extension region to comprise at least a portion of a surface of a not yet formed second structural layer, the second structural layer to have an end which is to extend beyond an end of the first structural layer by the extension region, the ends to contact, at least in part, the envelope, the surface of the second structural layer to contact, at least in part, a surface of the first structural layer, the method comprising the following steps:
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selectively exposing flowable material to a first exposure of said synergistic stimulation to form a first selected one of said first and second structural layers out of said material; forming a meniscus in said region which at least in part reduces said discontinuity; selectively exposing said meniscus, at least in part, to a second exposure of said synergistic stimulation whereupon said meniscus substantially transforms, wherein said exposure of said meniscus occurs prior to formation of a last layer of structure of said three-dimensional object; forming a coating of said flowable material over at least a portion of an upper surface of said first selected one, said upper surface comprising one of said surfaces of said first and second structural layers; and selectively exposing said coating to a third exposure of said synergistic stimulation to form a second selected one of said first and second structural layers which is different from said first selected one. - View Dependent Claims (29, 30, 57, 58, 59)
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31. An improved stereolithographic apparatus for forming a three-dimensional object on substantially a layer by layer basis from a material capable of selective physical transformation upon exposure to synergistic stimulation comprising means for forming successive layers of unsolidified material of desired thickness in preparation for forming layers of structure of said three-dimensional object and means for exposing said layers of unsolidified material to synergistic stimulation to form said layers of structure of said three-dimensional object, including means for forming a last layer of unsolidified material and means for exposing said last layer to synergistic stimulation to form a last layer of structure thereby completing formation of all layers of said three-dimensional object, the improvement comprising:
means for reducing at least part of an up-facing surface discontinuity between two layers by selectively exposing said unsolidified building material within at least part of said discontinuity to synergistic stimulation wherein said synergistic stimulation impinges on a surface of said material with an orientation close to perpendicular prior to exposing said last layer of structure of said three-dimensional object. - View Dependent Claims (60)
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32. An apparatus for reducing a surface discontinuity between first and second structural layers of a three-dimensional object being stereolithographically formed comprising a deviation between a down-facing region of a three-dimensional object surface and a desired object envelope, the down-facing region to comprise an end of a not yet formed first structural layer which is to contact at least in part the object envelope, and an extension region which is to comprise a portion of a lower surface of a not yet formed second structural layer, the lower surface to contact at least in part an upper surface of the first structural layer, the second structural layer to have an end which is to extend beyond the end of the first structural layer, and which is to contact, at least in part, the object envelope, comprising:
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a container containing a volume of flowable material, which material is capable of selective physical transformation upon selective exposure to synergistic stimulation, whereupon a working surface of the material is formed; at least one computer programmed to modify a building representation, wherein said building representation specifies a first exposure of said synergistic stimulation to form said first structural layer having a first cure depth, to specify selectively exposing material at the working surface to a second exposure of the synergistic stimulation to form a first fill layer, said fill layer having a first edge and a second edge and having an upper surface and being cured to a depth less than said first cure depth; wherein said at least one computer is further programmed to specify selectively exposing material to a third exposure of synergistic stimulation to form said second structural layer, wherein said lower surface of said second structural layer contacts at least in part said upper surface of said first fill layer, in accordance with said building representation; recoating means for forming an untransformed layer of said material over said upper surface of said first structural layer and said upper surface of said first fill layer; and forming means for selectively exposing material to said synergistic stimulation in accordance with said building representation. - View Dependent Claims (33, 34, 35, 65)
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36. An apparatus for reducing a surface discontinuity between first and second structural layers of a three-dimensional object being stereolithographically formed comprises a deviation between a down-facing region of said three-dimensional object surface and a desired object envelope, the down-facing region comprising an end of an already-formed first structural layer which contacts at least in part the object envelope, and an extension region comprising a portion of a lower surface of a not yet formed second structural layer, after formation the lower surface of said second structural layer contacting at least in part an upper surface of the first structural layer, and the second structural layer having an end which extends beyond the end of the first structural layer by the extension region, which end contacts at least in part the object envelope, wherein the first and second structural layers have thicknesses, comprising:
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at least one computer programmed to modify a building representation, wherein said building representation specifies coating over said first structural layer with a layer of desired thickness of said flowable building material in preparation for formation of said second structural layer and specifies selective exposure of said coating to said synergistic stimulation to form at least part of said second structural layer, to specify selectively exposing, at least in part, the extension region of the second structural layer to synergistic stimulation to expose material situated below the extension region to form a first fill layer; and forming means for selectively exposing said material to said synergistic stimulation in accordance with said modified building representation. - View Dependent Claims (37, 38, 39)
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40. An apparatus for reducing a surface discontinuity between first and second structural layers of a three-dimensional object being stereolithographically formed, said discontinuity comprising a deviation between an up-facing region of a three-dimensional object surface and a desired object envelope, the up-facing region comprising an end of an already-formed first structural layer, and an extension region comprising at least part of an upper surface of an already-formed second structural layer, the first structural layer having a lower surface contacting at least in part the upper surface of the second structural layer, and the second structural layer having an end which extends beyond the end of the first structural layer by the extension region, which end contacts at least in part the object envelope, wherein the first structural layer has an upper surface at about a working surface of flowable material capable of selective physical transformation upon exposure to synergistic stimulation, wherein the first and second structural layers have thicknesses, comprising:
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at least one computer programmed to modify a building representation to specify selectively exposing said material to a first exposure of the synergistic stimulation to form a first fill layer having a thickness less than the thicknesses of the first and second structural layers; and forming means for selectively exposing said material to said synergistic stimulation in accordance with said modified building representation. - View Dependent Claims (41, 42, 43)
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44. An apparatus for reducing a surface discontinuity between first and second structural layers of a three-dimensional object being stereolithographically formed from a flowable material capable of selective physical transformation upon exposure to synergistic stimulation, said discontinuity comprising a deviation between an up-facing region of a three-dimensional object surface and a desired object envelope, the up-facing region to comprise an end of a not yet formed first structural layer, an extension region comprising at least a portion of an upper surface of an already-formed second structural layer, the second structural layer having an end which is to extend beyond the end of the first structural layer by the extension region, and which ends contacts at least in part the object envelope, wherein the second structural layer has an upper surface which is to contact, at least in part, a lower surface of the first structural layer, the second structural layer having an upper surface situated at about a working surface of flowable material, comprising:
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at least one computer programmed to modify a building representation to specify forming a coating of said flowable material over at least part of said extension region in preparation for forming a first fill layer and selectively exposing said material to a first exposure of synergistic stimulation to form said first fill layer, and having a lower surface which contacts, at least in part, the extension region of the second structural layer; coating means for forming a coating over previously formed layers in accordance with said modified building representation; and forming means for selectively exposing said material to said synergistic stimulation in accordance with said modified building representation. - View Dependent Claims (45, 46, 47)
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48. An apparatus for reducing a surface discontinuity between a first and second structural layer of a three-dimensional object being stereolithographically formed said discontinuity comprising a deviation between a region of a three-dimensional object surface and a desired object envelope, the region to comprise an end of a not yet formed first structural layer, and an extension region, the extension region to comprise at least a portion of a surface of a not yet formed second structural layer, the second structural layer to have an end which is to extend beyond an end of the first structural layer by the extension region, the ends to contact at least in part the object envelope, the surface of the second structural layer to contact, at least in part, a surface of the first structural layer, and the first and second structural layers to have thicknesses, comprising:
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a container containing a volume of flowable material, the material being capable of selective physical transformation upon exposure to synergistic stimulation; at least one computer programmed to modify a building representation, wherein said building representation specifies a first exposure of said synergistic stimulation to form a first selected one of said first and second structural layers in accordance with a building representation, to specify selectively exposing said material to a second exposure of said synergistic stimulation to form a first fill layer having a first portion which contacts, at least in part, a portion of said first selected one; and wherein said building representation specifies selectively exposing said material to a third exposure of said synergistic stimulation, to form a second selected one of said first and second structural layers which is different from said first selected one, wherein said modified building representation specifies a time order of exposure to be one of the first exposure followed by the second exposure followed by the third exposure or the first exposure followed by the third exposure followed by the second exposure; and forming means for selectively exposing said material to said synergistic stimulation in accordance with said modified building representation.
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49. An apparatus for reducing a surface discontinuity between first and second structural layers of a three-dimensional object being stereolithographically formed from a flowable material capable of selective physical transformation upon exposure to synergistic stimulation, said discontinuity comprising a deviation between a region of a three-dimensional object surface and a desired object envelope, the region to comprise an end of a not yet formed first structural layer, and an extension region, the extension region to comprise at least a portion of a surface of a not yet formed second structural layer, the second structural layer to have an end which is to extend beyond an end of the first structural layer by the extension region, the ends to contact, at least in part, the object envelope, the surface of the second structural layer to contact, at least in part, a surface of the first structural layer, comprising:
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at least one computer programmed to modify said building representation, wherein said building representation specifies a first exposure of said synergistic stimulation to form a first selected one of said first and second structural layers out of said material, to specify selectively exposing a meniscus of said material to a second exposure of said synergistic stimulation whereupon at least a portion of said meniscus substantially transforms, and wherein said building representation further specifies selectively exposing said flowable material to a third exposure of said synergistic stimulation to form a second selected one of said first and second structural layers which is different from said first selected one; recoating means for forming a coating of untransformed material over an upper surface of said first selected one; meniscus forming means for forming a meniscus of said flowable material in said region which at least in part reduces said discontinuity; and at least one forming means for selectively exposing material to said synergistic stimulation in accordance with said modified building representation to transform said material to form said layers and to transform said meniscus to reduce said discontinuity. - View Dependent Claims (66, 67, 68, 69)
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50. A method for forming a three-dimensional object from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising the steps of:
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modifying an object representation, specifying, at least in part, a first layer of the object adjacent to a second layer in the object, said first and second layers specified to have thicknesses, and specified to form a surface which includes a deviation from a desired object envelope, to obtain a modified object representation further specifying forming a third layer, specified to have a thickness less than the thickness of said first and second layers, and attaching said third layer to at least one of said first or second layers of said object to reduce said deviation; successively forming layers of said material; and selectively exposing said layers of material to said synergistic stimulation in accordance with said modified object representation to obtain said three-dimensional object.
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51. An apparatus for forming a three-dimensional object from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising:
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at least one computer programmed to modify an object representation specifying, at least in part, a first layer of the object adjacent to a second layer of the object, said first and second layers specified to have thicknesses, and specified to form a region which comprises a deviation from a desired object envelope, to obtain a modified object representation further specifying forming a third layer, specified to have a thickness less than the thicknesses of said first and second layers, and attaching said third layer to at least one of said first or second layers to reduce said deviation; means for successively forming layers of said material; and means for selectively exposing said layers of material to said synergistic stimulation in accordance with said modified object representation to form said three-dimensional object.
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61. An improved stereolithographic apparatus for forming a three-dimensional object on substantially a layer by layer basis from a material capable of selective physical transformation upon exposure to synergistic stimulation comprising means for forming successive layers of unsolidified material of desired thickness in preparation for forming layers of structure of said three-dimensional object and means for exposing said layers of unsolidified material to synergistic stimulation to form said layers of structure of said three-dimensional object, including means for forming a last layer of unsolidified material and means for exposing said last layer to synergistic stimulation to form a last layer of structure thereby completing formation of all layers of said three-dimensional object, the improvement comprising:
means for reducing at least part of a down-facing surface discontinuity between a first and a second layer by selectively exposing said unsolidified building material within at least part of said discontinuity to synergistic simulation prior to exposing said last layer of structure of said three-dimensional object but after a layer of material is formed in preparation for formation of said second layer. - View Dependent Claims (62)
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63. An improved stereolithographic apparatus for forming a three-dimensional object, having an exterior surface, on substantially a layer by layer basis from a material capable of selective physical transformation upon exposure to synergistic stimulation, comprising means for forming successive layers of unsolidified material of desired thickness, including a last layer, in preparation for forming layers of structure of said three-dimensional object and means for exposing said layers of unsolidified material to synergistic stimulation to form said layers of said three-dimensional object, including formation of a last layer of structure thereby completing formation of all layers of said three-dimensional object, the improvement comprising:
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means for selectively exposing a layer of material of desired thickness to form at least a portion of an internal region of a layer of structure, said layer of structure having a z-range corresponding to said desired thickness; and means for forming at least a portion of said exterior surface of said three-dimensional object from at least one fill layer which has a thicknesses less than said desired thickness, and wherein said at least portion of said exterior surface corresponds to said z-range. - View Dependent Claims (64)
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Specification