US 6,581,456 B1Granted

Substrate bending stiffness measurement method and system

AssigneeXerox Corporation

InventorRobert A. Clark

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Abstract

A method and apparatus for measuring substrate bending stiffness and thereby basis weight on a real time basis. Provided is a corrugator having a plurality of parallel ribs, with one or more sheets of the substrate provided below the corrugator wherein a predetermined gap exists between a topmost sheet of the sheets and the corrugator. A vacuum is applied between the corrugator and the topmost sheet, wherein the vacuum is sufficiently large to raise the topmost sheet, thereby deflecting and bending it into a profile corresponding to the arrangement and size of the corrugator ribs and bending stiffness of the substrate. One or more sensors are provided for measuring the deflection of the topmost sheet. The vacuum, an air knife output and/or a fluffer output are then adjusted according to predetermined rules and the measured deflection.

Claims20

Dependent claims

A reprographic system comprising:

(a) a user interface configured to receive commands to the reprographic system for starting a reprographic process;
(b) an image input source comprising at least one of a scanner and a network connected digital input;
(c) a vacuum corrugated substrate feeder comprising:
(i) a corrugator feedhead having a plurality of parallel ribs;
(ii) a tray configured to hold a stack of sheets of the substrate at a fixed distance below the feedhead;
(iii) a vacuum source configured to provide a vacuum between the feedhead and a topmost sheet of substrate on the stack, wherein the vacuum source is sufficiently large to raise the topmost sheet, thereby deflecting and bending it into a profile corresponding to the arrangement and size of the plurality of parallel ribs and bending stiffness of the substrate;
(iv) at least one of an air knife and a fluffer configured to inject air into the top sheets of the substrate;
(v) at least one sensor configured to sense an upward deflection of the topmost sheet of substrate and produce a sensor output corresponding to the amount of upward deflection, thereby also corresponding to the bending stiffness of the substrate;
(vi) a system memory;
and
(vii) a control program configured to select preferred operating parameters corresponding to the bending stiffness of the substrate according to the sensor output and predetermined rules and adjust at least one of the air knife output and the fluffer output according to the selected parameters;
and
(d) a finishing unit for forming an image on the topmost sheet of the substrate.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/041,047Filed 7 Jan 2002
Published: US 2003/0126931 A110 Jul 2003
Granted: 24 Jun 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

G01N 3/20
Investigating strength properties of solid materials by application of mechanical stress: by applying steady bending forces
G01N 2203/0046
Pneumatic means: vacuum
G01N 2203/0258
Geometry of the test: non axial, i.e. the forces not being applied along an axis of symmetry of the specimen
G01N 2203/0417
Chucks, fixtures, jaws, holders or anvils: using vacuum