EP0127479A1

EP0127479A1 - Document transport system

Info

Publication number: EP0127479A1
Application number: EP84303603A
Authority: EP
Inventors: Harry James Charles Etherington; Paul Carter Joslin; George Rupert Rawson
Original assignee: REDIFFUSION COMPUTERS Ltd
Current assignee: REDIFFUSION COMPUTERS Ltd
Priority date: 1983-05-31
Filing date: 1984-05-29
Publication date: 1984-12-05
Also published as: GB8314890D0; JPS6071442A

Abstract

A document transport system comprising a cylinder (8) rotatable abouts its major axis, flexible bands (11, 12) wrapped around a portion of the circumference of the cylinder (8) and spaced apart in a direction parallel to the cylinder major axis, and receiving tray (1) and associated guide surface (2) arranged such that a generallyflat article placed on the tray (1) with one of its edges in contact with the guide surface (2) can be moved across the tray into the nip defined between the cylinder (8) and the flexible bands (11, 12). The cylinder and flexible bands are driven to cause an article introduced into the nip to be carried on the cylinder beneath the flexible bands in an orientation determined by the initial orientation of the article relative to the guide surface.

Description

The present invention relates to a document transport system.
Document transport systems are well known and are used for example to transport documents in a predetermined orientation past the reading head of an optical character reader. If reliable operation is to be obtained, it is necessary to ensure that the transport system flattens the document, positions it accurately relative to datum edges, and then moves it past the reading head in a controlled manner. The known transport systems perform adequately with documents of uniform size and condition but do not reliably handle documents with non-uniform characteristics, for example crumpled or creased documents, documents carrying extraneous items such as staples, or documents having a range of dimensions. Furthermore, the known transport systems are of considerable size and complexity and therefore their use involves considerable expense.
It is an object of the present invention to provide an improved document transport system.
According to the present invention there is provided a document transport system comprising a cylinder rotatable about its major axis, at least two flexible bands wrapped around a portion of the circumference of the cylinder and spaced apart in a direction parallel to the cylinder major axis, a receiving tray and associated guide surface arranged such that a generally flat article placed on the tray with one of its edges in contact with the guide surface can be moved across the tray into the nip defined between the cylinder and the flexible bands, and means for driving the cylinder and flexible bands to cause an article introduced into the said nip to be carried on the cylinder beneath the flexible bands in an orientation determined by the initial orientation of the article relative to the guide surface.
Preferably each of the flexible bands is continuous and passes around at least two pulleys arranged such that only one side of the length of band extending between the pulleys bears against the cylinder. The document receiving tray terminates in an edge between the bands and the cylinder adjacent to one of the points at which the bands and cylinder come into contact.. A document stripping device is provided which terminates in an edge located between the bands and the cylinder adjacent to the other point at which the bands and cylinder come into contact. Where three pulleys are provided, a first pulley may be located above the cylinder, a second pulley below the cylinder, and a third pulley on the side of the cylinder remote from the tray, the lengths of band extending between the first and second pulleys wrapping around approximately half the circumference of the cylinder.
A reading head may be located to scan documents held between the cylinder and bands.
A drive roller and co-operating pinch roller may be provided to guide and drive documents to the nip between the cylinder and the bands, the drive roller having its axis of rotation inclined to a normal drawn from the guide-surface such that a document against which the drive roller bears is moved into contact with and thereafter urged against the guide surface as it is simultaneously moved towards the nip. Preferably, the drive roller is mounted above the tray and the pinch roller may be located below the tray to contact the drive roller via an aperture in the tray. The drive roller preferably is provided with a resilient surface and may be supported such that it has a controlled degree of freedom of movement to accommodate documents having a variety of characteristics. The pinch roller is preferably crowned.
An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a schematic side view of a document transport system embodying the invention; and
Figure 2 is a view from above of the system shown in_Figure 1.

Referring to the drawings, the system comprises . a document receiving tray 1 parallel to the rotation axis of a cylinder 8 one edge of the tray is defined by a guide surface 2 which is orthogonal to the tray 1 or at an obtuse angle thereto. A drive roller 3 is mounted above the tray and bears against a free running roller 4 through an aperture in the tray. The axis of the roller 3 is inclined to the surface 2 such that as it rotates in the direction of arrow 5 any document located between it and the roller 4 is driven to the right in the drawings and is also urged towards the guide surface 2. Documents fed onto the tray 1 are thus fed forwards in the direction of arrow 6 (Figure 2) with one edge of the document in contact with the guide surface 2. It is also possible to have the drive roller 3 mounted below the tray with the free running roller 4 above the tray although this is not the presently preferred arrangement.
The tray 1 terminates in an edge 7 adjacent the surface of a cylinder 8 which is free to rotate about its major axis. The cylinder has a central portion 9 of greater diameter than end portions 10. Two flexible endless bands 11, 12 are wrapped around approximately half the circumference of the cylinder and also pass around three pulleys 13,14 and 15. The pulley 18 is driven by a motor 16 via a belt 17.
A document stripper 18 is located beneath the cylinder to separate documents from the cylinder and feed them into an outlet chute 19. Sensors 20 detect the presence of a document on the tray 1 and on the cylinder and may be used to control the energisation of the drive motor, and a reading head 21 is provided to scan a document on the cylinder.
In use, a document is placed on the tray 1 adjacent the guide face 2 in roughly the orientation that it is desired the document should maintain during its passage through the transport system. The document is then engaged between roller 4 and 5 and driven forwards towards the nip defined between the cylinder 8 and the flexible bands 11 and 12, any misalignment of the document being corrected as a result of the document being urged against the guide face 2. The document is then gripped between the cylinder 8 and the bands 11,12 and as a result is wrapped around the cylinder, moving with it past the reading head 21. The document is then stripped from the cylinder and discharged into the chute 19.
The described embodiment of the invention can reliably handle documents having a wide range of characteristics, for example, documents of different widths, lengths and thicknesses, documents comprising several layers of paper, and documents "which are creased, crumpled or have items such as staples inserted in them. The described embodiment is also relatively cheap to produce and yet compact as the position of document is achieved in a very short distance, generally only a fraction of the length of the document itself.
The receiving tray and guide face are preferably coated with a low friction material.
The surface roller 3 rendered flexible by being made of a suitable material which is slotted, while the surface of the roller 4 is crowned. This arrangement enables a wide variety of documents to be reliably handled. Further, the roller 3 may be mounted so as to have a controlled degree of freedom of movement in the vertical direction and in the horizontal direction to allow the system to handle for example abnormally thick documents.
The flexible drive bands 11 and 12 firmly hold documents in contact with the cylinder and can accommodate abnormal documents. They also assist in flattening any deformed documents. In the illustrated embodiment the bands 11 and 12 are driven by motor 16 and in turn drive the cylinder 8. It will be appreciated however that alternative drive arrangements could be provided, e.g. independent drives to the bands and the cylinder, or drive to the cylinder only. Furthermore, means may be provided for monitoring the speed of the drive to the system.
The reduced diameter of the end portions 10 of the cylinder makes it easy to remove debris falling from documents and also allows for extraneous items such as staples at the edges of documents.
The reading head 21 may of course take various forms depending on the information to be read, for example an optical character reader, a magnetic reader, or an electrostatic reader.

Claims

1. A document transport system comprising a cylinder rotatable abouts its major axis, at least two flexible bands wrapped around a portion of the circumference of the cylinder and spaced apart in a direction parallel to the cylinder major axis, a document receiving tray and associated guide surface arranged such that a generally flat article placed on the tray with one of its edges in contact with the guide surface can be moved across the tray into the nip defined between the cylinder and the flexible bands, and means for driving the cylinder and flexible bands to cause an article introduced into the said nip to be carried on the cylinder beneath the flexible bands in an orientation determined by the initial orientation of the article relative to the guide surface.

2. A document transport system according to claim 1, wherein each of the flexible bands is continuous and passes around at least two pulleys arranged such that only one side of the lengths of band extending between the pulleys bears against the cylinder, the document receiving tray terminating in an edge located between the bands and cylinder adjacent one of the points at which they come into contact, and a document stripping device is provided which terminates in an edge located between the bands and cylinder adjacent the other point at which they come into contact.

3. A document transport system according to claim 2, comprising a first pulley located above the cylinder, a second pulley located below the cylinder, and a third pulley located on the side of the cylinder remote from the tray, the lengths of band extending between the first and second pulleys wrapping around appoximately half the circumference of the cylinder.

4. A document transport system according to claim 1, 2, or 3 wherein the cylinder comprises a central portion and at least one end portion of a smaller diameter than the central portion.

5. A document transport system comprising a reading head located to scan documents held between the cylinder and bands.

6. A document transport system according to any preceding claim, comprising a drive roller located above the tray to feed documents to the nip between the cylinder and the bands, the drive roller having its axis of rotation inclined to a normal drawn from the guide surface such that a document against which the drive roller bears is moved into contact with and thereafter urged against the guide surface as it is simultaneously moved towards the nip.

7. A document transport system according to claim 6, comprising a further roller located below the tray and contacting the drive roller via an aperture in the tray.

8. A document transport system according to claim 6 or 7, wherein the drive roller is supported such that it has a controlled degree of freedom of movement to accommodate documents having a variety of characteristics.

9. A document transport system substantially as hereinbefore described with reference to the accompanying drawings.