Abstract: An improved process for forming photocurable three-dimensional objects using an improved curing process is disclosed. The build object is formed by using differential curing of the photocurable media material to form cured solid regions with discrete mechanical properties at selected locations to tailor a part's properties to individual needs.

Abstract: A method and apparatus for data transmission transmits both compressed and noncompressed data over each of a plurality of transmission paths. A data identification pattern is used to request a type of data from a memory having a plurality of data types stored within it. A handshaking control module is provided to select the correct type of data from the memory and place it on the output of the memory. The requested data type is then transmitted to a data decompression module via an interface. The data transmission can occur on any one of a plurality of data transmission paths when the data being transmitted is either Linework or Linework control data. When the data decompression module receives the data, it is then routed to any one of a plurality of data decompression systems based upon the results of the evaluation of the data identification pattern. The routing of the received data is wholly dependent upon the data identification pattern and independent of which transmission path the data was received on.

Abstract: A detoxification process for rendering three-dimensional objects formed by solid freeform fabrication techniques biocompatible for use in long-term dermal contact applications. The process nullifies cytotoxins normally present in objects formed by solid freeform fabrication techniques rendering such techniques as viable for the production of biocompatible devices such as stents, artery valve components, bone implant supports, pacemaker shells, surgical tools, and the like. In one embodiment, a custom hearing aid shell is produced by stereolithography from an acrylate photopolymer resin that was detoxified for long-term dermal contact application. The detoxification process makes three-dimensional objects created by solid freeform fabrication techniques available for products requiring biocompatibility.

Abstract: The present invention relates to a process for the production of three-dimensional articles by stereolithography using a radiation-curable composition comprising a mixture of at least one cationically polymerizable compound and/or at least one free radical polymerizable compound, at least one filler material and at least one photoinitiator for cationic and/or radical polymerization. An organic viscosity stabilizer material may be brought into contact with the composition to substantially delay or prevent undesirable viscosity increase and subsequently premature polymerization. A filler material is optionally added to the composition in an effective amount to at least delay or prevent a significant increase in viscosity and polymerization. The process is particularly suitable for stabilizing resins in stereolithography baths.

Abstract: A method and apparatus for signal phase alignment. A pulse is produced and a reference clock signal having a first frequency with one or more clock edges is produced. An alignment clock signal is generated having the first frequency aligned with the pulse. The first frequency of the alignment clock signal is then realigned with the pulse. The alignment clock signal is generated using the pulse and aligning one of the clock edges of the reference clock signal with the pulse edge. The alignment clock signal is realigned using a plurality of delayed clock signals based on the reference clock signal. Each of the delayed clock signals has one or more edges. The plurality of delayed clock signals are latched based on the pulse and the delayed clock signal having an edge nearest to the pulse is selected.

Abstract: The present invention includes a method of transferring data when some of the data is masked. A mask table is provided to a storage device where it is duplicated and stored with the duplicate. The duplicate data is compared to the original data for a data protection function. A mask index counter and mask bit counter maintain provide values for specific data that are to be processed. The counters are programmable so that if a transfer error occurs, counter values for the next data after the previously transferred good data is calculated and loaded therein. The present invention also has the capability not to transfer the last requested sector if that sector is masked. The present invention evaluates whether a stop count value equals a stop threshold value when a sector is identified as being masked. The stop count value is incremented for each sector that is read from the first storage device, regardless of whether that sector is to be transferred or masked.

Abstract: A device to turn on a disk formatter's write gate and NRZ line drivers with minimal delay from a sector pulse. The device utilizes a look-ahead scheme to asynchronously qualify a sector pulse to drive the write gate and enable the NRZ output drivers. The write gate and NRZ line drivers are conditionally enabled by a sector pulse and are held in the enabled state until the disk formatter provides an enable signal. The enabled NRZ line drivers provide binary zeros until actual data is provided to the drivers.

Abstract: The present invention relates to a process for the production of three-dimensional articles by stereolithography using a radiation-curable composition having at least one cationically polymerizable compound and/or at least one free radical polymerizable compound, at least one filler material and at least one photoinitiator for cationic and/or radical polymerization. An organic viscosity stabilizer material is brought into contact with the composition to substantially delay or prevent undesirable viscosity increase and subsequently premature polymerization. A filler material is added to the composition in an effective amount to at least delay or prevent a significant increase in viscosity and polymerization.

Abstract: Priority levels and bump values are assigned to requestors for access to a system resource. When access requests are received, arbitration of the requests is made in accordance with the assigned priorities, bump values, and the received access requests. If a high priority level access request is granted, then the same request will be held off for a successive number of requests as set by the bump values. In cases where the access is required for more than one request/grant cycle, the priority level access can be retained as long as required.

Abstract: Memory testing is performed by a dedicated hardware system, initialized by a system processor and employing the processor's DMA capability to allow the system to execute other programs without having to wait until memory testing is completed. The same hardware can be utilized as a memory scrubber.

Abstract: Pipelined image data transfer which tessellates and quads the data while transferring. The output data from the transfer can be selectively in quad or linear format. Such tessellating and formatting is performed in-line using alternate buffers for pipelining so that there is effectively no delay for performing the operations. The operations are performed by unique input and output buffer and image storage addressing.

Abstract: Resource master and slave combinations operating from separate local clocks asynchronously even though there may be wide speed variations among the devices, eliminating the need to synchronize the trailing edges of generated control signals with the local clock so as to free access to the resource as soon as possible without introducing timing or logic hazards.

Abstract: Clipping individual rows or columns of pels from patterns stored as pels is accomplished by passing quads of pels through a clipper before rotation is effected. Integral numbers of quads are clipped by skipping their address when reading from the pattern store or inhibiting their transfer. This permits more detailed pages to be composed for printing.

Abstract: Bus master for use in computer system includes logic for determining the number of words remaining to be transferred in a DMA operation to supply signals to permit arbitration to start for the next DMA request, thereby avoiding an idle cycle. A timeout state machine is also included to prevent the bus master state machine from hanging in a state with no exit. Errors can be masked to permit analysis of system problems.

Abstract: A character generator with multidirectional scan and variable line and character (or symbol) size capability is disclosed. Universality is implemented by producing a serial binary stream which can be used to print or display in any of eight combinations of scan direction and progression, that is, for scan direction left to right, or vice versa, progressing up or down, or scan direction top or bottom or vice versa, progressing left or right. In formatting the serial binary stream, a font is accessed (for basic symbol definition), which selectively provides for orthogonal scan of the symbol definitions. Variable line size is implemented by terminating a symbol row (or line) based on a predetermined size criteria regardless of the comparable font dimension and "filling" up to the line size to the extent the corresponding font dimension is less than the predetermined size criteria.

Abstract: A character generator with multidirectional scan and variable line and character (or symbol) size capability. Universality is implemented by producing a serial binary stram which can be used to print or display in any of eight combinations of scan direction and progression, that is, for scan direction left to right, or vice versa, progressing up or down, or scan direction top to bottom or vice versa, progressing left or right. In formatting the serial binary stream, a font is accessed (for basic symbol definition), which selectively provides for orthogonal scans of the symbol definitions. Variable line size is implemented by terminating a symbol row (or line) based on a predetermined size criteria regardless of the comparable font dimension and "filling" up to the line size to the extent the corresponding font dimension is less than the predetermined size criteria.