Paper transportation device

Abstract

A paper transportation device 100 is provided with an obliquely transported condition detection unit 404 and a sensor movement controller 402. The obliquely transported condition detection unit 404 is configured to detect an obliquely transported condition of a sheet of paper based on a detection result of the travel-directional front end of the sheet of paper by obliquely transported condition detection sensors 113a and 113b. The obliquely transported condition detection sensors 113a and 113b are arranged in predetermined positions on a document transportation path. The sensor movement controller 402 is configured to move the obliquely transported condition detection sensors 113a and 113b in accordance with the width size of the sheet of paper.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority under 35 U.S.C, §119 to Japanese Patent Application No. 2008-080749 filed on Mar. 26, 2008. The entire disclosure of Japanese Patent Application No. 2008-080749 is hereby incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a paper transportation device, and more particularly to a paper transportation device to detect accurately a condition of a sheet of paper being transported in an oblique orientation.[0004]2. Background Art[0005]Recent image forming apparatuses have a variety of functions in addition to a copy function. For example, they have a facsimile transmission function, a scan function, a print function, a staple function, and a punch function. Furthermore, image forming apparatuses with an automatic document feeder (ADF) have been produced in response to the increased functional diversity. The ADF is configured to feed ...

AI Technical Summary

Benefits of technology

[0011]Accordingly, aspects of the present invention have been created to solve the above-mentioned problems occurring in the conventional practice, and to produce a paper transportation device for accurately detecting an obliquely transported condition of a sheet of paper.

[0022]With the configuration, the obliquely transported condition detection sensors are moved to positions to differentiate sufficiently detection timings by the obliquely transported condition detection sensors. In the positions, a period of time is maximized since one of the obliquely transported condition detection sensors detects one of the sides of the sheet of paper until the other of the obliquely transported condition detection sensors detects the other of the sides of the sheet of paper. Accordingly, regardless of width of a sheet of paper to be transported, it is possible to detect accurately an obliquely transported condition of the sheet of paper. Consequently, it is possible to detect preliminarily an obliquely transported condition of a variety of kinds of paper and prevent occurrence of troubles such as scanning of an obliquely oriented image from an obliquely transported document and formation of an obliquely oriented image onto a sheet of paper. In other words, it is possible to provide a high quality printed material. Thus, the present invention best suits the ADF to scan a variety of kinds of documents.

[0024]With this configuration, when a user aligns both of the width directional opposed sides of the sheet of a document with the alignment plates, at least either of the obliquely transported condition detection sensors is automatically moved with the moved alignment plate(s). Thereby the obliquely transported condition detection sensors are arranged to detect accurately an obliquely transported condition of the sheet of document every time alignment is performed. In other words, even when a user roughly puts the document on the disposition plate, it is possible to detect accurately an obliquely transported condition of the sheet of the document. Consequently, it is possible to output a printed material without deteriorating its quality and to prevent output of unnecessary printed material caused by an obliquely transported condition of the sheet of document.

[0025]Furthermore, it is possible to obtain the width size of the sheet of paper and to move the pair of obliquely transported condition detection sensors in accordance with the obtained width size, that is, the width directional opposed sides of the sheet of paper.

[0026]With this configuration, it is possible to move automatically and appropriately the pair of obliquely transported condition detection sensors to positions to detect accurately an obliquely transported condition of the sheet of paper, for example, when a predetermined contact sensor is arranged in a predetermined position on the disposition plate and is configured to obtain the width size of the sheet of paper. Accordingly, it is not necessary for a user to put a document on the disposition plate using great care regarding accurate orientation and the like. In other words, a user is able to place readily and roughly a sheet of a document on the disposition plate. Furthermore, the quality of the printed material will not be deteriorated and a user is able to save time when aligning the sheet of paper because it is possible to detect accurately an obliquely transported condition of a sheet of document without strictly aligning the sheet of document.

Problems solved by technology

In this case, it is difficult to provide appropriately the above-mentioned functions.

Specifically, when the document / printing-paper is transported in an oblique orientation, quality of the printed material will be deteriorated.

Accordingly, this results in an increase of wasted printed material.

This is especially a problem when the document / printing-paper is manually supplied through a manual feeding tray and the like.

Consequently, it is impossible for the obliquely transported condition detection sensors to detect accurately an oblique condition of a sheet of standard form paper with greater width.

Therefore, it is impossible to apply the an to a device with an automatic paper feeding function (e.g., ADF) without arbitrarily changing the art.

Otherwise, it is impossible to prevent the oblique condition of the document.

Additionally, the same problem occurs when a plurality of sheets of printing paper are pulled out of a paper feeding tray / cassette one by one.

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