US 4,381,447 AGranted

Method and apparatus for evaluating and sorting sheets in a high speed manner

AssigneeBrandt, Inc.

InventorsStephen J. Horvath, Steven R. Wilcox

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Abstract

Electronic solid state circuitry incorporating the microprocessor for automatically controlling document handling apparatus. Sheets are advanced from a stack of sheets arranged in an infeed stacker and are moved one at a time at high speed through an examining location where sensors examine the sheets to determine their condition. The microprocessor periodically initiates an adjustment in the brightness level and gain control level of the lamps and sensor elements employed in the sensor array; tracks each sheet as it moves through the document handling apparatus; and evaluates the outputs developed by the sensors to determine the fitness of each sheet. A gating roller assembly, under control of the microprocessor, is operated to divert each sheet toward one of a plurality of output stackers according to the results of the evaluation performed by the microprocessor. Timing of the electronic circuitry is controlled by timing signals derived from the document handling apparatus to synchronise the electronic circuitry with the document handling apparatus. The sheets are tested during their high speed movement for a variety of conditions which are operator selectable and which conditions are operator adjustable.

Claims12

Dependent claims

Microprocessor-based control means for operating document handling apparatus comprising means for moving sheets in a first direction at spaced intervals along a predetermined path;

sensing means for detecting the passage of sheets and for detecting predetermined characteristics of said sheets;
at least one of said sensing means being adapted to generate a signal upon the passage of the leading edge of each sheet at the location of said one sensing means;
means for generating timing pulses at a rate which is a function of the velocity of said sheets moving along said predetermined path;
multi-stage counter means being pulsed by said timing means;
memory storage means;
means responsive to a leading edge signal for transferring the contents of said multi-stage counter means to a predetermined location in said memory storage means;
said microprocessor-based control means further including means for periodically sampling the contents of said counter means and for determining the difference between the count stored in said predetermined location in said memory storage means and the count developed by said multi-stage counter means at the time said counter means is sampled wherein the difference in said count represents the location of said sheet along said predetermined path;
document condition examining means positioned at spaced intervals along said path;
means for temporarily storing examined conditions;
means responsive to predetermined difference values between the status count stored in said predetermined location in said memory storage means and the count sampled from said multi-stage counter means for examining the conditions in said temporary storing means.

7 more elements

A method for evaluating sheets to determine their fitness including plural sheet evaluating means arranged at predetermined spaced locations comprising the steps of;

moving sheets at spaced intervals in a first direction along a predetermined path which moves said sheets past said sheet evaluating means;
generating pulses at a rate representative of the velocity of the sheets moving in said predetermined direction;
counting said pulses;
automatically restarting said count when said count reaches a predetermined maximum value;
storing said count at a predetermined location in a memory when the leading edge of a sheet passes a predetermined location;
periodically comparing the present count being developed against the count stored in said predetermined location for determining the difference therebetween;
examining the results of one of said sheet evaluating means when said difference lies within a predetermined range;
examining the results of a second one of said sheet evaluating means when said count lies within a second predetermined range different from said first range.

5 more elements

Dependencies are inferred from the claim text.