Method and apparatus for assembling sets of documents

I claim:

1. A method for assembling sets of documents, comprising the steps of:

storing a plurality of reference brightness patterns, each in association with a document code corresponding to a specific type or category of documents;

subsequently, loading documents of at least one of said specific types or categories into one of a plurality of feeding stations;

storing at least one feeding station code identifying a feeding station in association with a document code of one of said specific types or categories of documents loaded in that feeding station;

subsequently, reading set configuration instructions including at least one selected document code;

selecting at least one feeding station identification code stored in association with said at least one selected document code;

feeding at least one document from at least one of said feeding stations designated by said at least one selected feeding station identification code;

optically scanning a brightness pattern from at least parts of said at least one document fed from said at least one feeding station;

comparing the scanned brightness pattern with the reference brightness pattern or patterns stored in association with the respective selected document code or codes;

generating at least one signal signifying whether a specified minimum extent of agreement between the compared brightness patterns has been found; and

including said at least one document into a set if said signal signifies that said specified minimum extent of agreement between the compared brightness patterns has been found.

2. A method for assembling sets of documents, comprising the steps of feeding a plurality of documents and gathering at least some of said documents into sets with preselected compositions, wherein:

optically scanning brightness patterns from at least parts of at least some of said documents,

comparing each of said scanned brightness patterns with at least one reference brightness pattern of a specific type or category of documents, said reference brightness pattern or patterns being stored in a memory,

generating signals signifying whether a specified minimum extent of agreement between the compared brightness patterns has been found, and

controlling the composition of gathered sets of documents in accordance with said signals,

wherein said reference brightness pattern is obtained by scanning from an exemplary copy of the type or category of documents using a photosensitive scanner, which scanner is subsequently also used for the scanning of the brightness patterns which are compared with the at least one stored reference brightness pattern.

3. A method for assembling sets of documents, comprising the steps of feeding a plurality of documents and gathering at least some of said documents into sets with preselected compositions, wherein:

optically scanning brightness patterns from at least part of at least one of said documents,

comparing each of said scanned brightness patterns with at least one reference brightness pattern of a specific type or category of documents, said at least one reference brightness pattern being stored in a memory,

generating signals signifying whether a specified minimum extent of agreement between the compared scanned and reference brightness patterns has been found, and

controlling the composition of gathered sets of documents in accordance with said signals,

wherein scanning of the brightness patterns includes calculating a running average over a detection interval of at least 0.5 mm.

4. A method for assembling sets of documents, comprising the steps of feeding a plurality of documents and gathering at least some of said documents into sets with preselected compositions, wherein:

optically scanning brightness patterns from at least parts of at least one of said documents,

comparing each of said scanned brightness patterns with at least one reference brightness pattern of a specific type or category of documents, said at least one reference brightness pattern being stored in a memory,

generating signals signifying whether a specified minimum extent of agreement between the compared scanned and reference brightness patterns has been found, and

controlling the composition of gathered sets of documents in accordance with said signals,

wherein scanning of the brightness patterns is carried out through a window, the documents are passed along the window in a direction of transport and the window measures at least 0.5 mm in the direction of transport.

5. A method for assembling sets of documents, comprising the steps of:

storing a plurality of reference brightness patterns in a memory, each in association with a document code corresponding with a specific type or category of documents;

subsequently, loading documents of at least one of said specific types or categories into at least one of a plurality of feeding stations;

optically scanning a brightness pattern from at least parts of at least one document of at least one of said types or categories of documents loaded into said feeding station or stations;

comparing the at least one scanned brightness pattern with at least one of said reference brightness patterns;

generating at least one signal signifying whether a specified minimum extent of agreement between the compared brightness patterns has been found, wherein, if said specified minimum extent of agreement between a particular one of the scanned brightness patterns and a particular one of the reference brightness patterns is found, said signal represents the document code associated to said particular reference brightness pattern;

storing at least one feeding station code in a memory in association with the document code represented by said signal, said at least one feeding station code identifying the feeding station provided with documents of said specific type or category from which said particular brightness pattern has been scanned;

subsequently, reading set configuration instructions including at least one selected document code;

selecting at least one feeding station identification code stored in association with said at least one selected document code;

feeding at least one document from said at least one selected feeding station designated by said at least one selected feeding station identification code; and

including said at least one document fed in accordance with said set configuration instructions in a set.

6. A method according to claim 5, wherein, after being fed, the documents are transported in a direction of transport along at least one stationary photosensitive scanner and the brightness pattern is scanned during transportation.

7. A method according to claim 6 wherein, said set configuration instructions including a selected document code are read by also passing a main document along said photosensitive scanner, scanning marks on said main document using said scanner, and converting said scanned marks into set configuration instructions.

8. A method according to claim 5, wherein:

the feeding of at least a subset of the documents is carried out successively from a common source, and

in reaction to a signal signifying that the specified minimum extent of agreement between the compared brightness patterns has been found, the gathered documents are discharged as a set at such a moment, that the document of which the scanned brightness pattern showed the specified minimum extent of agreement with the stored reference brightness pattern occupies a predetermined position relative to the beginning or the end of said subset or of a next subset of documents.

9. A method according to claim 8, wherein at least two reference brightness patterns are stored, each in association with a particular control code.

10. A method according to claim 9, wherein at least two of said particular control codes are mutually different, each of said control codes being associated with an integer value greater than or equal to zero, said integer value indicating the number of documents to be fed and gathered between a signal associated with the respective code and the discharge of the gathered documents.

11. A method for assembling sets of documents, comprising the steps of:

storing a plurality of reference brightness patterns in a memory, each in association with a document code;

selecting at least one of said document codes;

feeding and collecting a plurality of documents, wherein at least some of said documents are fed successively from a common source;

optically scanning brightness patterns from at least parts of said documents from said common source;

comparing the scanned brightness patterns with the reference brightness pattern stored in association with the selected document code;

generating signals signifying whether a specified minimum extent of agreement between the compared brightness patterns has been found; and

controlling the composition of sets of documents in accordance with said signals by discharging collected documents as a set responsive to a signal signifying that the specified minimum extent of agreement between the compared brightness patterns has been found, wherein the discharging is carried out at such a moment, that each document of which the scanned brightness pattern showed the specified minimum extent of agreement with the compared reference brightness pattern occupies a predetermined position relative to the beginning or the end of a collected and discharged set of documents fed from said common source.

12. A method according to claim 11, wherein a reference brightness pattern to be stored is obtained by positioning a template with a pattern defining a plurality of boxes over the document, visually determining brightness values of the document in at least two specified ones of said boxes, and inputting and storing said determined values as reference brightness values for said specified boxes.

13. A method according to claim 12, wherein each stored reference brightness value is a minimum or maximum limit value.

14. A method according to claim 11, wherein data defining the location of a brightness pattern on a document are stored in association with at least one of the reference brightness patterns.

15. A method according to claim 11, wherein the brightness patterns are each composed of a plurality of successive binary values, each of said values indicating whether the average scanned brightness in a specific section of a document is greater than or smaller than a limit brightness value for that section.

16. An apparatus for assembling sets of documents, comprising:

a plurality of feeding stations for feeding documents, each feeding station being provided with a store-tray for accommodating a plurality of documents to be fed;

a transport track for transporting documents received from said feeding stations;

a control unit for controlling said feeding stations and the transport track;

an optical scanner for scanning a brightness pattern from a document, said scanner being arranged along the transport track downstream of said feeding stations for scanning documents fed from said feeding stations;

a memory tier storing a plurality of reference brightness patterns, each in association with a document code, and a plurality of document codes, each in association with a feeding station code;

means for inputting the reference brightness pattern in the memory;

signal processing means programmed for comparing a scanned brightness pattern with a reference brightness pattern stored in the memory and for generating signals signifying whether a specified minimum extent of agreement between the scanned brightness pattern and the reference brightness pattern stored in the memory is found;

the signal processing means being coupled to the control unit for transmitting said signals to the control unit; and the control unit being coupled with each of said feeding stations for sending commands to the feeding stations and being programmed for sending commands to the feeding stations in accordance with inputted set configuration instructions including selected document codes and in accordance with feeding station codes stored in association with said selected document codes.

17. An apparatus according to claim 16, wherein the photosensitive scanner is stationary in longitudinal direction of the transport track.

18. An apparatus according to claim 16, comprising a gathering station located downstream of the feeding stations, the optical scanner being located downstream of the feeding stations and upstream of the gathering station.

19. An apparatus according to claim 16, comprising a gathering position located downstream of the feeding station or stations, the transport track being adapted for groupwise discharging gathered documents from the gathering position, and the control unit being programmed for activating the transport track in reaction to said signals if said signals indicate that said minimum extent of agreement between the scanned brightness pattern and the reference brightness pattern has been found.

Description Submit all comments and votes

BACKGROUND OF THE INVENTION

The invention relates to a method for assembling sets of documents wherein documents are successively fed and gathered into sets.

According to a method known from practice, the composition of sets of documents which have been fed separately is controlled by counting, during the formation of each set, the number of documents being fed and discharging gathered documents collectively when according to the count a specified number of documents have been gathered. This number should be set at the desired number of documents per set.

A drawback associated with this known method is that the risk of counting errors is substantial. Moreover, an error also affects the composition of subsequent sets, so that following an error the subsequent sets do not contain the correct documents either but contain one or more documents of a next or a preceding set. Counting errors may for instance arise when two documents are being fed simultaneously instead of consecutively. A further drawback of this known method is that the number of supplied documents that are to be discharged simultaneously as a set has to be set anew whenever a set consisting of a different number of documents than the preceding set is to be gathered. This means that this method does not enable efficient implementation of the composition of sets consisting of different numbers of documents in random order.

According to U.S. Pat. No. 3,260,517, for the composition of sets of documents, use is made of several feeding stations each loaded with a number of identical documents. For the composition of the sets, documents are fed by one or more of the feeding stations. For each set, different combinations of feeding stations can be selected for feeding documents. The selection of the feeding stations occurs in accordance with signals which have been read from a main document. These signals represent the set composition instructions for a set to be composed starting from the main document in question.

A drawback of this known method is that for each series of sets to be composed, it must be specified which documents are to be loaded into which feeding stations, and that these documents must then be loaded into the feeding stations prior to the preparation of that series of sets.

A further drawback is that if an error is made in drawing up the specification of the documents to be loaded into the feeding stations or in loading those documents, so that a feeding station is loaded with other documents than was envisaged in drawing up the main document, a different document than intended will be added to the main document upon activation of the feeding station in question.

SUMMARY OF THE INVENTION

The object of the invention is to provide a method whereby in a simple manner the feeding of documents to a set can be controlled for the preparation of sets with different configurations in a random order, without the necessity of providing particular marks on the documents to be recognized and without the necessity of interpreting a brightness pattern scanned from the document.

This object is realized in accordance with the present invention in that brightness patterns are optically scanned from at least parts of at least some of the documents and the scanned brightness patterns are each compared with at least one reference brightness pattern of a specific type or category of documents, which reference brightness pattern or patterns are stored in a memory. Signals signifying whether a specified minimum extent of agreement between the compared brightness patterns has been found are generated, and the composition of gathered sets of documents is controlled in accordance with these signals.

Because a brightness pattern of at least a part of a document is stored as a reference and a brightness pattern scanned from a document is compared with the stored reference brightness pattern, random brightness patterns present on a specific type or category of documents can be used to determine whether any agreement exists and to generate a signal in response to which the control system controls the composition of the set in the desired manner. Accordingly, it is not necessary to provide specific marks with a predetermined meaning on a document. Any distinguishable brightness pattern present on a document of a particular type or category can be used.

The invention can further be embodied in an apparatus adapted for the practice of the method according to the invention.

Particular elaborations and embodiments of the invention are set forth in the depending claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Hereinafter the invention is further explained on the basis of an exemplary embodiment with reference to the drawing. In the drawing:

FIG. 1 is a cutaway side elevation of an apparatus for practicing the method according to the invention;

FIG. 2 is a flow diagram representing a method according to the present invention;

FIG. 3 is a flow diagram representing a setting part of a second method according to the invention;

FIG. 4 is a flow diagram representing the operating part of the second method according to the invention;

FIG. 5 is an example of a document with a fixed intended position relative to the beginning of each set; and

FIG. 6 is an example of a document with a fixed intended position relative to the end of each set.

DETAILED DESCRIPTION OF THE INVENTION

First the most preferred exemplary embodiment of a system according to the invention for composing sets of documents as shown in FIG. 1 is further explained.

The system is equipped with a plurality of feeding stations F1-F6 for feeding documents 20-25.

The first five feeding stations F1-F5 are each designed as a station for singulating and feeding sheets from a stack. Each of these feeder stations F1-F5 comprises a paper storage tray 5, a supply roller 6, a separation roller 7, a transport roller 8 and a pair of feed rollers 9. An example of a separation device suitable for use in a feeder station F1-F5 according to the exemplary embodiment shown, is described in more detail in applicant's U.S. Pat. No. 5,362,037, incorporated herein by reference.

The last feeding station F6 is designed as a printer with a tray 10 for printing sheets and a pair of feed rollers 11 for feeding a printed sheet at an appropriate time. Preferably, the printer is so designed that the printing of a sheet is always completed before the sheet reaches a waiting position between the feed rollers 11.

The feeding stations F1-F6 are united with transport means 3, 4 to form feeding-transport units, which can be connected to each other. The transport means 3 connected with the feeder stations F1-F5 each comprise mutually staggered conveyor belts 12, 13, partly located opposite each other. The downstream conveyor belt 13 of an upstream transport unit extends to a point opposite an upstream conveyor belt 12 or 14 of a next, downstream transport unit 3 or 4. Thus a document can be passed on to a next transport unit 3 or 4. The last transport unit 4 comprises opposite conveyor belts 14, 15 which end straight opposite to each other.

The feeding-transport units equipped with a feeder station F1-F5 are provided with legs 31 which, in assembled condition, project into a subjacent station. By virtue of these legs 31 the downstream conveyor belt 13 remains clear of a supporting surface when a disassembled feeding-transport unit is set down on such supporting surface.

The system further comprises a gathering and aligning station 16 for gathering documents in a gathering position into a set in the form of an aligned stack with document edges substantially in alignment on one side.

The aligning station 16 is designed as a head station with a supply track, an aligning surface with a movable stop 26 and a discharge track 36 in line with the aligning surface 19. The supply track is formed by transport rollers 27, 28, 29, 30 and guides 61, 62 and the aligning surface is formed by a portion of a conveyor belt 18 that runs over a support 19. Documents supplied by the transport unit 4 can be passed by way of this supply track to the aligning surface 19.

The documents can be transported in the direction of supply as far as the stop 26 and then be discharged in the opposite direction. The aligned document edges form the trailing edge of the stack, which is advantageous in folding the stack. In the folding station 32, the position of each fold is defined with respect to the trailing edge of the stack of documents.

The stop 26 is fixed to the conveyor belt 18. The stop can be moved by running the conveyor belt 18.

Arranged opposite the aligning surface 19 are pressing means 17 which are movable in the direction of the stop 26 approximately parallel to the aligning surface 19, are capable of exerting some pressure on the aligning surface 19 and have a greater coefficient of friction relative to documents than does the aligning surface. By displacing the pressure means in the direction of the stop 26, documents present between the aligning surface and the pressure means can be urged against the stop, so that the document edges on the side of the stop 26 are aligned relative to each other.

The aligning surface 19 is convexly curved in the direction of displacement of the stop 26. The pressure means are designed as an endless belt 17 tensioned with a particular tension, one end thereof extending along the aligning surface 19. Because of the tension of the endless belt 17 of the pressure means, this belt exerts, in the area adjacent the stop 26, a uniformly distributed pressure in the direction of the aligning surface 19.

The conveyor belt 17 has a greater coefficient of friction relative to the material of the documents than does the conveyor belt 18. By driving the conveyor belt 17 for exerting a force on a document located between the belts 17 and 18 in the direction of the stop 26, this document will move over the belt 18 against the stop 26. A next document, which has been passed partly between the preceding document and the conveyor belt 17, will move over the preceding document and likewise abut against the stop 26 when the belt 17 is driven in the direction of the stop 26. Thus successive documents can be aligned relative to each other.

The system further comprises a folding station 32 for folding documents coming from the aligning station 16. Such a folding station is described in more detail in applicant's U.S. Pat. No. 5,090,671, which is incorporated herein by reference.

The pin of the transport roller 30 is pivotally suspended so that the transport roller can also serve as a pressure roller for keeping the documents to be folded pressed against one of the folding rollers of the folding station. Arranged opposite the transport roller 30 is a pivotable guide 41 which in an upwardly pivoted position guides documents to the gathering position and in a downwardly pivoted position allows documents to pass from the gathering position to the folding station.

To the folding station 32 connects an inserting station 33. This inserting station 33 is equipped with two trays 34, 35 for envelopes. As a basis for such an inserting station 33 the "in2" can be used, which is produced and marketed by applicant. A method for selecting an envelope tray for feeding an envelope depending on documents to be inserted, is described in applicant's European patent application 92200364.5, which is incorporated herein by reference.

In the preparation of a set of documents intended for a postal item using the system shown, the feeding stations F1-F6 feed documents to the transport units 3, 4. The aligning station 16 aligns the documents, forming a stack with document edges substantially aligned on one side. This stack is supplied to the folding station 32.

At least some of the documents to be gathered into a set can be fed at such moments that these, before being moved relative to each other downstream of the feeding stations 1, 2 and upstream of the folding station 32, are transported in a configuration in which those documents overlap each other and each next one of those documents projects relative to the preceding document in the same direction transverse to the edges to be aligned.

In that case, a number of the documents of a set, or possibly an entire set of documents, are gathered already upon being fed and are transported in gathered condition. As a result, a large number of documents can be transported simultaneously, which in turn offers the advantage that a large number of documents can be processed per unit time.

Each next document of a number of overlapping documents is staggered in the same direction relative to a preceding document. Thus corresponding edges of these documents can be readily aligned.

The documents are preferably fed in such a manner that during alignment a document which is smaller in a direction transverse to the document edges to be aligned is moved over a greater distance than a document that is greater in the direction referred to. This prevents a situation where during displacement of a large document a document whose edge has not been aligned yet and which is not carried along by that larger document retains its position or at any rate is not completely aligned.

For scanning brightness patterns of the documents as fed, which are separately transported to the aligning station 16, an optical detector 64 is arranged along the transport track 4 downstream of the feeding stations F1-F6 and upstream of the aligning station 16, this optical detector 64 being movable in transverse direction of the transport track and stationary in the longitudinal direction of the transport track. For processing and storing the scanned brightness pattern, the apparatus comprises an analog-digital converter and an overwritable memory in which the converted signals can be stored.

The feeding of documents by the feeding stations F1-F6 and the transport of the documents along the transport tracks 3, 4, 36 and the belts 17 and 18 of the gathering station 16 is controlled by a control unit 37. The apparatus further comprises signal processing means 38 which are programmed for comparing a scanned brightness pattern with a reference brightness pattern stored in the memory. For this purpose, commercially available components can be used. In the apparatus according to the exemplary embodiment shown, the control unit 37 and the signal processing means 38 are integrated in the same data processor 39, which is connected with processors 42-47, associated with the feeding stations, for communication with those processors 42-47. In turn, the processors 42-47 associated with the feeding stations are designed for controlling the associated feeding stations F1-F6 on the basis of instructions received from the control unit 37. The last feeding station F6, which is designed as a printer, naturally comprises further processors for controlling the printing of the documents. The communication between the processor 47 associated with the last feeding station F6 and the printer only consists of commands to print and feed a next sheet and `action completed` reports. The last feeding station may for instance be designed as a high-speed feeding station rather than a printer, without this making any difference to the communication with the control unit.

The method according to the invention can be used in the apparatus according to the exemplary embodiment shown, for various purposes. Two practical examples will hereinafter be described and elucidated partly with reference to the flow diagrams shown in FIGS. 2-4. In these flow diagrams the most essential steps of the two practical examples are shown.

The first practical example comprises determining the moment at which subsets composed of documents successively fed by the last station F6 and gathered in the gathering station 16, are to be discharged collectively by driving the belts