FR2890277A1 - Sheet recto and verso scanning method for e.g. fax machine, involves scrolling recto of sheet by parametering scan head based on detected characteristics during another recto scrolling operation - Google Patents

Abstract

The method involves scrolling a recto (R) of a sheet (F), detecting characteristics e.g. sheet type, of the recto by a scan head, and scrolling a verso (V) of the sheet. A tray (1) receives the sheet to be scanned. The characteristics are then stored in a memory of a control unit (10). The recto of the sheet is scrolled another time by parametering the scan head based on the detected characteristics during the former recto scrolling operation.

Description

The invention relates to a method of digitizing a document by

  scrolling the document in front of a scanning head in a single direction of scrolling.

  BACKGROUND OF THE INVENTION Document processing devices, and more particularly facsimile machines, are known comprising a scanning head (or scanner) and a routing channel for driving a document to be digitized to the scanner head. scan from a document tray to be scanned and evacuate to an output bin. In these devices, the document is scanned by scrolling the document in front of the scanning head in a single direction of scrolling. The scan settings of the scan head are set at the factory to medium values for relatively good scanning regardless of the type of document or its contents. As a result, scanning may be insufficient for very clear or very dark documents, or complex documents.

  OBJECT OF THE INVENTION It would therefore be advantageous to have a means to improve the quality of scanning in these devices.

BRIEF DESCRIPTION OF THE INVENTION

  For this purpose, according to the invention, there is provided a method of digitizing a document by scrolling the document in front of a scanning head in a single direction of scrolling, comprising the steps of: - first scrolling a recto of the document document and detect characteristics of the front side by means of the scanning head, - scroll one back of the document, - scroll the front of the document a second time by setting the scan head according to the characteristics detected during the first scrolling from the front.

  Thus, it is possible to set the scanning head for each document based on, for example, the type of document detected, the densities of the tones, etc.

  According to a first embodiment, the method comprises the step of detecting characteristics of the back when scrolling the back and, after the second scroll of the front, the step of scrolling a second time the back by setting the head depending on the characteristics detected during the first scrolling of the back.

  This implementation allows a fast double-sided scanning and relatively good quality.

  According to a second embodiment, the method comprises the following steps of: - scrolling a second time on the back of the document and detecting characteristics of the back by means of the scanning head, - scrolling a third time On the front side of the document, scroll the back of the document a third time by setting the scanning head according to the characteristics detected during the second reverse scrolling.

  This implementation allows a double-sided scanning of relatively good quality without requiring the use of a high capacity memory.

BRIEF DESCRIPTION OF THE DRAWINGS

  The invention will be better understood in the light of the following description of a particular mode of implementation with reference to the single appended figure which is a schematic view of the internal path of the sheets in a document scanning device implementing the process of the invention.

  DETAILED DESCRIPTION OF THE INVENTION

  Referring to the single figure, the method of the invention is described in the context of an implementation on a scanning device (or scanner) front and back for example a fax machine.

  The scanning device comprises a tray 1 receiving the sheets to be scanned. From the tray 1 extends a routing channel 2 which opens tangentially in a loop path 3 opposite a portion of which extends a scanning head 4.

  Downstream of the digitizing head 4, the loop path 3 comprises a first end 5 which opens into an ejection channel 6 and a second end 7 which is tangent to the first end 5 and which also opens into the channel of FIG. ejection 6. Between the ends 5, 7 extends a switching member 8.

  Drive rollers are arranged in a manner known per se in the routing channel 2 and the loop path 3 for feeding the sheets from the tray 1 to the loop path 3 via the routing channel 2 and circulate the leaves in the loop path 3 in the direction indicated by the arrows in front of the digitizing head 4. In the figure, a sheet F (recto R and verso V) is distinguished, the front edge of which is to reach the scanning head 4. A drive roller 9 is disposed at the ejection channel 6 and is connected to an actuator motor so as to be rotatable in both directions.

  A control unit 10 is connected to the drive motors of the drive rollers and the scanning head 4 to control them.

  The scanning method according to the invention will now be described.

  The scanning process starts with the steps 2890277 4 of first scrolling the front side R of the sheet F by means of the drive rollers and detecting characteristics of the front side R by means of the digitizing head 4. The characteristics detected relate to - for example, the type of document, text or image; the nature of the paper, matte, satin or glossy; the densities of tones, very light or very dark areas ... and more generally any characteristic of the document that can be used to improve the quality of the digitization. These characteristics, hereinafter called scanning characteristics, are then stored in a memory of the control unit 10.

  Once the detection of the characteristics has been completed, the sheet F is retained in the ejection channel 6 instead of being evacuated. The driving roller 9 is then actuated in opposite direction and the switching member 8 is controlled to orient the sheet F towards the second end 7 and engage it in the loop path 3 in the direction indicated by the arrows of FIG. in the first run of the back V of the sheet F in front of the scanning head 4. In the first run of the back V of the scanning characteristics of the back V are detected by means of the scanning head 4. The characteristics the V side are memorized in the control unit. The sheet F then crosses again the switching member 8 to reach the ejection channel 6 where it is retained by the drive roller 9.

  The driving roller 9 is then actuated in opposite direction and the switching member 8 is controlled to orient the sheet F towards the second end 7 and engage it in the loop path 3 in the direction indicated by the arrows of FIG. so as to scroll a second time the recto R of the sheet F in front of the scanning head 4. It is then proceeded to the digitization 2890277 5 front R by means of the digitizing head 4 set according to the scanning characteristics of the front side R memorized.

  Once the digitization of the front R completed, the sheet F is once again retained in the ejection channel 6 instead of being evacuated. The driving roller 9 is then actuated in opposite direction and the switching member 8 is controlled to orient the sheet F towards the second end 7 and engage it in the loop path 3 in the direction indicated by the arrows of FIG. so that the back V of the sheet F is scanned a second time in front of the scanning head 4. The back side V is then digitized by means of the scanning head 4 set according to the scanning characteristics of the reverse side. V memorized.

The sheet F is then evacuated.

  As a variant, when the memory of the digitizing device is of low capacity, the digitization characteristics are not detected during the first traverse of the V-side. This first scrolling of the V-side V then serves only for the reversal of the sheet F. At the moment of the second scrolling of the recto R, only the characteristics of the digitization of the recto R which are used for the digitization of the recto R are therefore present in the memory. The digitization characteristics of the back V are detected and memorized during the second scrolling. These two digitizing characteristics are used for the digitization of the back V which occurs during a third scroll of the V side consecutive to a third scroll of the recto R made to return the sheet F. The invention is not limited to what has just been described, but on the contrary includes any variant falling within the framework defined by the claims.

  In particular, it will be noted that it is possible by the method of the invention to scan only the front of a document: it is then not proceeded to the detection of the characteristics of digitization of the back side when scrolling the back and the sheet is evacuated after the second run of the front.

Claims (3)

  1. A method of scanning a document (F) by scrolling the document in front of a scanning head (4) in a single direction of scrolling, characterized in that it comprises the steps of: - scrolling a recto a first time (R) of the document and to detect characteristics of the front side by means of the scanning head, - to scroll a back (V) of the document, - to scroll a second time the front of the document by setting the scanning head according to the characteristics detected during the first run of the front.   2. Method according to claim 1, characterized in that it comprises the step of detecting characteristics of the back (V) during the scrolling of the back and, after the second scroll of the front (R), the step of scrolling a second time the reverse by setting the digitizing head (4) according to the characteristics detected during the first scrolling of the lens.   3. Method according to claim 1, characterized in that it comprises the following steps of: - scrolling a second time the back (V) of the document (F) and detecting characteristics of the back by means of the scanning head (4), - scroll a third time on the front (R) 30 of the document, - scroll a third time the back of the document by setting the scanning head according to the characteristics detected during the second scrolling back.