GB2054535A - Sheet handling device - Google Patents

Abstract

A sheet handling device suitable for photocopying machines has rotatable suction or blowing means, preferably rollers 5,6 provided on a platen 1. In a suction mode, to position a sheet, the rollers gripping the sheet are rotated and preferably two sets of such rollers are provided one set moving the sheet in an 'X' axis direction and the other set moving the sheet in a 'Y' axis direction. In a blowing mode the rollers are not driven but act in consort to provide an air cushion, other means being provided to move and stop the sheet in a required position on the platen surface. Sensors may be provided to assist positioning and a turning device may be provided at one or more edges of the platen using suction or blowing or a combination of the two to conduct the sheet around a semicircular path from the platen and back again for reverse copying. <IMAGE>

Description

SPECIFICATION Handling devices The present invention relates to apparatus for handling documents and other laminae and whilst suitable for other purposes is particularly suitable for photocopying apparatus.

Document feed in photocopying apparatus is often fed manually to a copying station, however belt feed may be used when rapid and continuous feed is required. Problems in handling thin and fragile documents often occur with belt feed and is often necessary when handling such documents to return to manual feed.

It is an object of the present invention to provide apparatus in which documents of various thicknesses, strength and texture can be handled quickly and without damage to the document.

Apparatus for handling documents according to the invention comprises a platen, rotating gas means on the platen arranged to grip a document and to move the document in at least one direction.

Preferably the suction means comprises a plurality of rollers each roller provided with apertures on its cylindrical outer face and means for providing suction to the interior of the roller in communication with the apertures.

In order to position a document at a copying station relative to the copying optical axis it is advantageous to provide two sets of rollers each set acting to move a document at right angles to the other in the plane of the platen so that 'X' and 'Y' axis movement of the document may be provided.

'X' and 'Y' axis movement is a term commonly used in the micro photographic art as movement parallel to the sides of the document or lamina and in the plane of the document or lamina.

To ensure full automation of 'X' and 'Y' axis movement it is advantageous to provide sensors on the platen surface to detect the edges of a document and which sensors through suitable control means control both sets of rollers to position the document relative the document copying axis. Such a position may be central or may be to one side of the optical axis.

Whilst suction is normally applied to the rollers it is possible to provide a slight, positive pressure to the rollers and to immobilise these when moving documents, movement to documents being provided by additional gas jets or suction at the side or sides of the platen in a manner similar to my Australian Patent No. 504,035 and my U.S. Patent No. 4,176,947. Document location in such a case may be provided in a similar fashion to the aforesaid patents.

In order to ensure document flatness an optically flat translucent cover plate may be placed over the platen.

It is often a requirement to turn a document to be copied and for this purpose a curved extension to the platen may be provided at at least one side of the platen. The extension may have static or moving gas ducts to blow or suck a document to the curvature of the extension.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 'shows in perspective a platen according to the invention with 'X' and 'Y' document movement, Figure 2 shows a detail of one of the suction blowing rollers used in the platen of Figure 1 and Figure 3 shows an extension to the platen of Figure 1 with provision for document turning.

In Figure 1 a document platen 1 is shown mounted above a base plate 2 by means of bearing blocks 3.

Between the platen and base plate are mounted bearing blocks 4 which carry sets of X axis rollers 5 and Y axis rollers 6, each set of rollers being movable by means of chain or belt drives 7 and 8 respectively and motors 9. The rollers protrude slightly through the platen as shown in Figures 1 and 2 so that apertures 10 in the rollers connected to a vacuum or pressure line 11 can act on a document placed on the platen.

Sensors 12 of a known kind are positioned on the upper surface of the platen 1. These are connected to suitable control means (not shown) for positioning the document in a required position on the platen relative a copy axis (not shown).

Figure 3 shows an extension on one, two or each side of the platen for document turning. A roller 15 is mounted at the centre of curvature 16 of a curved extension member 17 which initially is in the plane of platen 1. The roller is perforated or foraminous and may be solid with perforations or carry a foraminous smooth meshed material; and has means for applying gas at a pressure above or below atmospheric pressure to the perforated or foray in nous surface. Similarly the extension member 17 may have a perforated orforaminous surface with means for applying gas at a pressure above or below (that is a vacuum) atmospheric pressure to the surface of member 17.

In an alternative arrangement (not shown) member 17 may be provided with suction or pressure conducting slats with a perforate or foraminous surface, the slats extending across the width of member 17 and movable by drive means to assist document movement.

Depending on document consistency it may be preferable to suck a document around the extension but in some cases it may be preferable to blow the document around. It is for this reason that the opposed components 15 and 17 are provided to either suck or blow. One component may suck and one blow or both may blow to achieve an air cushion effect.

In order that the edge of the document does not tend to dig in to the extension member 17, an auxiliary roller may be provided at one or more points around the surface of member 17 and these may be assisted by blowing air through the surface of member 17.

In order to allow copied documents to move off the platen extension member 17 may be removed from the platen plane either by swinging it upwardly or in the case where member 17 is formed of a number of slats it can be withdrawn in the manner of a roller blind.

Claims (9)

1. Apparatus for handling documents or other laminae comprising a platen, rotating gas means on the platen arranged to grip or lift a document and means to move the document in at least one direction.

2. Apparatus as claimed in Claim 1 wherein the gas means comprises a plurality of rollers, each roller provided with apertures on its cylindrical outer face and means for providing suction to the interior of the roller in communication with the apertures.

3. Apparatus as claimed in Claim 1 wherein the gas means comprises a plurality of rollers, each roller provided with apertures on it cylindrical outer face and means for providing a pressure above atmospheric pressure to the interior of the roller in communication with the apertures.

4. Apparatus as claimed in any one of Claims 1 to 3 wherein two sets of rotating gas means are provided, each set being a set of rollers axially aligned at right angles to the other set in the plane of the platen so that when a suction is applied to the rollers and when rotary movement is imparted to the rollers X' and/or Y' direction movement may be imparted to a document on the platen.

5. Apparatus as claimed in Claim 4 wherein sensors are provided on the platen surface to detect the edges of a document on the platen, the sensors being enabled through control means to control the sets of rollers to position a document of the platen to a required position on the platen.

6. Apparatus as claimed in any one of Claims 1 to 5 wherein a translucent plate is provided above the platen.

7. Apparatus as claimed in any one of Claims 1 to 6 wherein an extension is provided at at least one side of the platen,the extension comprising means for conducting a document around a curved path and depositing a document so conducted back on the platen for reverse copying.

8. Apparatus as claimed in Claim 7 wherein the extension comprises two opposed foraminous surfaces following a substantially semi circular path from a point substantially level with the plane of the platen to a point above the platen.

9. Apparatus substantially as described with reference to the accompanying drawings.