Real time diagnostic system for reprographic machines

Claim 1

A reproduction machine for making copies from original documents having at least a first paper path through which sheets of paper are passed by transport devices during reproduction operations to various stations in said machine for operation thereon, and a diagnostic system for examining the operation of said transport devices moving said sheets through said paper path, said diagnostic system comprising: paper path sensing means located along said paper paths for sensing the passage of paper sheets as they are moved therethrough; clock means for generating data representative of machine operating time; addressable memory means for storing data representative of machine operating time and corresponding to paper sheet passage past said sensing means for each of a preselected number of paper sheet passages, said addressable memory means continuously updated, deleting old sheet passage data and storing current sheet passage data to maintain said sheet passage data for said preselected number of paper sheet passages; fault detection means for detecting a fault condition; non-volatile memory means for storing said sheet passage data corresponding to said preselected number of paper sheet passages on receipt thereof from said addressable memory means upon detection of a fault condition by said fault detection means; and means for selectively accessing said memory containing said time representations of said sheet passage.

Claim 10

A method for examining the operation of a reproduction machine having at least a first paper path for circulating paper sheets therethrough and including paper path sensors along said paper path, including the steps of: a. sensing passage of a paper sheet past paper path sensors; b. storing information regarding the time of paper sheet passage past said paper path sensors in an addressable memory for a plurality of paper sheets, whereby information is stored for an series of operations of said reproduction machine; c. continuously updating said information by deleting sheet passage information for the oldest sheet passage and adding information rgarind the most recent sheet passage; and d. moving said stored information from said addressable memory to a long term storage device on an occurrence of a preselected condition.

Claim 11

A method for examining the operation of a reproduction machine having at least a first paper path for circulating paper sheets therethrough and including paper path sensors along said paper path, including the steps of: a. sensing passage of a paper sheet past paper path sensors; b. storing information regarding the time of paper sheet passage past said paper path sensors in an addressable memory for a plurality of paper sheets, whereby information is stored for an series of operations of said reproduction machine; c. continuously updating said information by deleting sheet passage information for the oldest sheet passage and adding information rgarind the most recent sheet passage; and d. moving said stored information from said addressable memory to a long term storage device on an occurrence of a preselected condition.