US 6,241,243 B1 · Method of and apparatus for detecting abnormal paper feeding

Abstract

A method and apparatus for detecting an abnormal paper feed such as a paper jam in a printing press which can reduce the work load for an operator and prevent productivity and printing quality from being lowered by detecting the elapsed time of travel of a first sheet of paper from a paper feeder to a register, with the time corresponding to the number of sheets reaching the register. This number is compared to a number of paper sheets stored in a memory. When there is an agreement between the compared sheet numbers, normal paper feeding is indicated. When the detected number of sheets is more or less than the number stored in memory, abnormal paper feeding is indicated and further paper feeding is interrupted. A number less than the required number is indicative of paper remaining on a feeder board from a previous printing operation. A number larger than the required number is indicative of a paper jam.

Claims4

Dependent claims

A method of detecting abnormal paper feeding during a printing operation, comprising the steps of:

detecting the number of papers fed to a printer by a paper feeding signal generator generating a signal in response to paper feeding after a start of a paper feeding operation;
detecting whether or not a paper exists on a feeder board by a paper existence detector located thereon;
and
detecting abnormal paper feeding in accordance with a relation between said number of the papers fed and existence or non-existence of said paper on the feeder board, and
wherein said abnormal paper feeding is judged when said number of the fed papers detected by said paper existence detector is less than a preset fixed number.

2 more elements

Dependencies are inferred from the claim text.

Method of and apparatus for detecting abnormal paper feeding

Life of this patent

Method of and apparatus for detecting abnormal paper feeding

Life of this patent

Abstract

Claims4