Continuous paper feeding device and printer incorporating the same

Abstract

A tractor feeds a perforated continuous paper sheet to a printing position. The feeding force of a fusing device located downstream of the printing position is set larger than the feeding force of the tractor in order to apply tension to the continuous paper sheet at the printing position. A braking device located upstream of the tractor applies a braking force balancing with the feeding force of the fusing device to the continuous paper sheet. The braking force of the braking device is varied depending upon the properties of the paper sheet or the environmental conditions. This arrangement makes it possible to stabilize the feeding state even under situations where the sheet feeding force is likely to become unstable, thereby realizing printing without any deviation from the predetermined position. Further, this arrangement can also prevent hole breakage to occur.

Description

RELATED APPLICATIONS [0001] The present application claims priority to Japanese Patent Application No. 2000-259553 filed Aug. 29, 2000, the entire content of which is hereby incorporated by reference. TECHNICAL FIELD OF THE INVENTION [0002] This invention relates to continuous paper feeding devices for feeding continuous paper sheets, and in particular, to printers for printing images on perforated printing paper sheets. BACKGROUND OF THE INVENTION [0003] Conventional printers adapted for printing on continuous paper sheets employ a tractor feeder which is capable of horizontally feeding printing paper sheets as a feeding device for feeding continuous paper sheets in order to realize their downsizing. The tractor feeder is configured to feed a printing paper sheet by causing feed pins of a rotary-driven endless tractor to sequentially engage perforations arranged with a predetermined pitch longitudinally of the printing paper sheet. [0004] As is often the case with such continuous p...

AI Technical Summary

Benefits of technology

[0008] The present invention also provides a continuous paper feeding device which is free from the hole breakage problem.

[0009] The present invention also provides a printer which is capable of printing on a continuous paper sheet with a higher positioning precision.

[0011] With this continuous paper feeding device, when a continuous printing paper sheet supplied from the paper supply device is fed by the tractor, the controller controls the braking force applied by the braking device according to the braking force set by the braking force setting device. Accordingly, a high feeding precision can be ensured because the continuous paper sheet is applied with an optimized braking force, even under such situations as to cause the paper feeding force to become unstable. Further, it is possible to inhibit the occurrence of hole breakage.

[0013] The printer of the above construction is capable of printing images onto a continuous paper sheet with a high positioning precision. The feeding speed on the downstream side of the printing device is desirably made higher than that of the tractor to prevent the continuous paper sheet from slackening at a location adjacent the printing device. Even in this case, the balance between the feeding forces respectively working on the upstream and downstream sides of the tractor can be maintained by the braking force applied by the braking device, thereby ensuring a high print position precision.

Problems solved by technology

The occurrence of heavy hole breakage results in feeding the printing paper sheet, thereby causing a deviation from the predetermined printing position.

For this reason, if the balance between the feeding forces respectively working on the upstream and downstream sides of the feeding device, such as the tractor, is lost even slightly, a deviation in the positioning of the paper sheet relative to the photosensitive drum occurs due to such an imbalance, thus resulting in a lowered precision in positioning for printing.

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