Well, we have all heard about the incoming boom in the 3D Printing Industry as key patents dealing with everything from metal sintering to other fabrication techniques are set to expire this month all the way to the start of 2015. Here is a list of some of the key patents within the 3D Printing industry set to expire along with their dates.

5,569,349- Expired October 29, 2013
Current Assignment Data Unavailable
U.S. Patent No. 5,569,349 to Almquist et al. entitled “Thermal Stereolithography” discloses an apparatus of and method for providing 3D objects through the principles of stereolithography using flowable materials. The patent also discloses the rapid substitution of materials throughout part building and the use of support materials that are easily removable from the finished part. Using a CAD system, the apparatus directs the nozzle to selectively dispense material at appropriate areas to form the part. The flow is then blocked, allowing the material to harden, and the next section is formed in the same manner. For parts needing support, a second material (e.g., wax, thermoplastic, hot melt glue) can be used to fill voids. By using a second material with a different melting point, the second material can be removed from the final part more readily.
5,587,913 – Expired December 14, 2013
Assigned to Stratasys
U.S. Patent No. 5,587,913 to Abrams et al. entitled “Method Employing Sequential Two-Dimensional Geometry for Producing Shells for Fabrication by a Rapid Prototyping System” discloses a method for producing 3D objects using a computer-generated specification of a solid object to interleave the planning and building phases of production on a slice-by-slice basis. Because the method does not require an explicit evaluation of the entire shell of the object at the outset, it ostensibly reduces the total time required to generate a finished part. The method can be operated with CAD and STL data and can also be employed to create non-planar objects.
5,597,589 – Expiring January 28, 2014
Assigned to DTM Corporation
U.S. Patent No. 5,597,589 to Deckard entitled “Apparatus for Producing Parts by Selective Sintering” discloses an apparatus for producing a 3D object from powder. The apparatus comprises a means for successively dispensing a plurality of layers of powder onto a target surface, an energy source (e.g., a laser), and a controller for directing the energy source at locations of each dispensed layer of powder at the target surface to fuse the powder and form a cross-section of the desired object. To avoid undesirable shrinkage of the object being produced, the apparatus further comprises a temperature control means (e.g., an exhaust) for moderating the temperature difference between the unfused and fused powder.
5,609,812 – Expiring March 11, 2014
Current Assignment Data Unavailable
U.S. Patent No. 5,609,812 to Childers et al. entitled “Method of Making a Three-Dimensional Object by Stereolithography” discloses a method of producing a 3D object from a medium that is solidifiable upon exposure to synergistic stimulation (e.g., UV or IR radiation). The invention improves upon a known stereolithographic method that involves selectively exposing layers of material to a beam of synergistic stimulation in a pattern to build up the 3D object layer by layer, where the pattern includes paths of exposure defined by vectors. The improvement disclosed in this patent comprises a method of identifying an endpoint of a first vector and a beginning point of a second vector, scanning the synergistic stimulation along the first vector at a fixed velocity, and shuttering (i.e., mechanically blocking) the synergistic stimulation when it reaches the endpoint of the first vector. The method further comprises directing the synergistic stimulation in a pattern to the beginning point of the second vector, unshuttering the stimulation when it reaches the beginning point, and scanning the stimulation along the second vector at a constant velocity.
5,609,813 – Expiring March 11, 2014
Current Assignment Data Unavailable
U.S. Patent No. 5,609,813 to Allison et al. entitled “Method of Making a Three-Dimensional Object by Stereolithography” discloses an apparatus and method of producing a 3D object from a medium that is solidifiable upon exposure to synergistic stimulation. The method involves applying a layer of flowable material, generating and sequencing a pattern of exposure paths for the layer corresponding to a cross-section of the object, and exposing the exposure paths to synergistic stimulation according to the sequencing to form a layer of the 3D object. This process is repeated until the object is formed, but with the step of sequencing being altered with a different sequence of exposure on at least one subsequent layer.
5,610,824 – Expiring March 11, 2014
Assigned to 3D Systems
U.S. Patent No. 5,610,824 to Vinson et al. entitled “Rapid and Accurate Production of Stereolithographic Parts” discloses an apparatus and method for producing a 3D object from a medium that is solidifiable upon exposure to radiation. The method involves providing a container with the medium and generating a beam of radiation––having first and second intensities that differ from each other––at the medium to form cross-sections of the object. The method further comprises scanning a first line on the material with the beam having the first intensity and scanning a second line on the material with the beam having the second intensity. By using a beam with different intensities, the laser can be directed over portions of the material without curing any appreciable amount. This can be particularly useful for large and complex objects, where a more powerful laser is required.
5,503,785 – Expiring June 2, 2014
Assigned to Stratasys
U.S. Patent No. 5,503,785 to Crump et al. entitled “Process of Support Removal for Fused Deposition Modeling” discloses a process for producing 3D objects having overhanging portions freely suspending in space. The process involves dispensing a first, solidifiable material in a predetermined pattern to deposit multiple layers that define a 3D object and a separate 3D support structure. The 3D support structure lies under the overhanging portions of the object, which require support during layer deposition. A space is left between the underside of the overhanging portions of the object and the top side of the supporting structure. A second, release material is dispensed into the space in a multiple-pass deposition process coordinated with the dispensing of the first material. The second material is of a different composition than the first material so that a breakable bond is made with the first material. This allows the support structures to be readily separable from the overhanging portions of the object, leaving only the object behind after removal.