Fault tolerance in high volume printing presses
First Claim
1. A method of operation in a modular digital color printing press to reduce module fault delays, said method including the steps:
- (a) providing at least one spare printing module at the downstream end of a serial array of the normally operative printing modules; and
(b) upon fault of a module in the array, cascading the data groups respectively representing sheets to be printed, downstream one printing module commencing at the faulty printing module.
10 Assignments
0 Petitions
Accused Products
Abstract
A method of reducing the `downtime` of the printing line involves the inclusion of at least one spare printing module, and a method of transferring digital representations of page images between modules. As soon as a fault is detected, a digital image data describing the sheet printed by the faulty module is transferred to the adjacent printing module downstream from the faulty module. The data in this module is simultaneously sent to the module downstream of it. This process repeats until a page image is sent to the spare printing module, which is best located as the most downstream of all the printing modules. Once all of the data has been transferred, printing can recommence. If this data transfer can occur in less than the time required to print a sheet, the line can continue printing without stopping, and without any wastage of printed copies. If more than one spare printing module is included at the end of the printing `assembly line`, then more than one simultaneous fault can be accommodated without productivity loss.
75 Citations
17 Claims
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1. A method of operation in a modular digital color printing press to reduce module fault delays, said method including the steps:
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(a) providing at least one spare printing module at the downstream end of a serial array of the normally operative printing modules; and (b) upon fault of a module in the array, cascading the data groups respectively representing sheets to be printed, downstream one printing module commencing at the faulty printing module. - View Dependent Claims (2, 3, 4)
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5. A method of restoring operation in a modular digital color printing press prior to the correction of the fault causing operation of one module to fail said method including the steps:
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(a) providing at least one additional spare printing module to the number of printing modules required for the printing task in the absence of a fault, said spare printing module being the most downstream of the printing modules for which faults are to be compensated; (b) transferring data representing the page or sheet to be printed to a downstream printing module after detection of a fault in a faulty printing module; and (c) transferring data in said downstream printing module to the printing module downstream of said downstream printing module prior to or substantially simultaneously with the transfer of data into said downstream printing module from said faulty printing module. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12)
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13. In a digital printing system comprising (i) a plurality of printing modules serially arranged along a print output transport path, (ii) means for receiving the output prints from said modules and transporting such prints serially downstream to form multi-print-page packets, and (iii) means for providing digital representations of a plurality of page images respectively to said printing modules, a fault control system for reducing delay due to a fault occurrence, a printing module, said fault control system comprising:
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(a) means for signaling the occurrence of a fault in an identified module; (b) a spare printing module located at the downstream end of said array of printing modules; and (c) means for cascading the digital page image representations respectively downstream one module from the faulty module through to said spare module. - View Dependent Claims (14, 15, 16, 17)
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Specification