GB2063763A

GB2063763A - Methods of checking book blocks

Info

Publication number: GB2063763A
Application number: GB7938029A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-11-02
Filing date: 1979-11-02
Publication date: 1981-06-10
Also published as: GB2063763B

Abstract

To avoid errors in the assembly of the signatures of folded sheets which together make up a book block, each different signature has at least two spaced narrow lines extending transversely across the outer side of the fold of the signature arranged in a way which is unique to that signature. The signatures are scanned optically in turn and the resulting scan is compared with that of a correctly assembled book block to determine whether the book block is acceptable or not. <IMAGE>

Description

SPECIFICATION Methods of checking book blocks This invention relates to the checking of book blocks.

In the manufacture of books, signatures, that is a collection of pages produced from a folded sheet or sheets are collected in appropriate order to form an assembly of signatures comprising the complete text of the book, the assembly being known as a bdok block. The signatures are sewn or adhered together and bound into a cover. It has been found that one of the main reasons for books being returned from a retailer is due to some form of mis-collation in assembling the correct signatures to form the book. Commonly either the signatures are in a wrong sequence or there is a double insertion of one signature. Some precaution is taken against errors in assembly of book blocks by means of short bands printed down the folds of the signatures at different positions along the folds in accordance with the different signatures.The bands are arranged so that they appear in one or more staggered series across the spine of the book block so that a mis-located signature should be obvious to visual inspection. However errors do occur partially because the bands have to be narrow in order not to intrude into the edges of the pages visible within the book and a slight mis-folding of the signature can result in a band not appearing at all at the outer corner of the folded signature. Also printers do not like applying such marks to the signatures because of the requirement to then fold the signatures accurately and the risk of intrusion of part of the band into the printed page.

This invention provides a method of checking book blocks comprising applying to each different signature to be made up into a book block at least two spaced narrow lines extending transversely across the outer side of the fold of the signature, the arrangement of the lines being arranged to be unique to each different signature and carrying out an optical scan of the assembled signatures comprising scanning along each signature in turn and comparing the results of the scan with the scan of a correctly assembled book block to determine whether the block is acceptable or not.

The thin lines extending transversely across the fold may intrude slightly into the printed page but are hardly visible and therefore do not cause a problem.

The following is a description of a specific embodiment of the invention, reference being made to the accompanying drawings in which: Figure 1 is a diagrammatic view of a back of book block with the signatures marked in the conventional manner; Figure 2 is a view of part of a book block with the signatures marked in accordance with one system according to the invention; and Figure 3 is a view of part of the back of a book block with the signatures marked in accordance with an alternative system.

Referring firstly to Fig. 1 of the drawings, there is shown a back of a book block indicated generally at 10 comprising a collection of signatures 11 each bearing a band 1 2 marked on the fold of the signature and extending lengthwise of the fold. The bands 1 2 are printed at different locations along the signature to distinguish the different signatures making up the book. Typically the bands are about 2 to 3mm., wide and 8 to 10 mm.

long.

The bands are so marked that when a collection of signatures to form a book is arranged in the correct order, the bands form one or more diagonal lines extending across the end of the book block.

A signature is formed by folding a sheet on which a number of pages are printed and since folding is carried out relative to the edge of the paper and not the printing on it, it is quite possible for the bands applied by the printer to miss or at least partly miss the fold in the signature as indicated at 1 3. When that occurs a wrongly placed signature may not be obvious to visual inspection and part of the band will be visible on the printed pages of the book which is obviously un-desirable.

Two alternative methods in accordance with the present invention will now be described for overcoming the problem. First referring to Fig. 2 of the drawings, each signature 11 of the book is printed with two spaced feint lines 14, 1 5 extending transversely across the signature of the location where the outer side of the fold will be made. The first line 1 4 is located adjacent one end of the signature and is in a position which will be substantially the same for all signatures. The second line 1 5 is spaced from the first line 14 by a distance unique to that signature. The book block is then scanned using an image device to scan signature by signature using an imaging device to scan the two marks. The distance between the two marks can thus be established for every signature and recorded as a digital number.One mark is used to start or trigger the measuring device and the other to stop it.

The scanner is connected to a micro-processor programmed to compare the results of the scan of each signature with a recording of a correctly assembled book to indicate whether or not the book being scanned is correct or not.

Since the transverse lines 1 4, 1 5 extend across the fold, the actual position of the fold is much less crucial than the bands previously used and even though the lines may intrude slightly into the printed page of the book, they are feint and are hardly noticable. Also vertical mis-alignment of the signatures can be tolerated since provided the lines 14, 1 5 are visible to the scanner, the scanner can "read" them.

Figs. 3 show an alternative manner of the marking the books in which each signature 11 has an outer pair of transverse lines 1 6, 1 7 disposed at a predetermined distance apart and from one edge of the book which dimensions are common to all signatures. Two intermediate lines 1 8 1 9 are also marked on each signature between the lines 1 6 and 1 7. There are a number of equally spaced discrete positions between the lines 1 6 and 1 7 and lines 1 8 and 1 9 are marked in selected ones of the discrete positions according to the signature.

The arrangement thus provides a marking system which can be unique to each signature and which need occupy only a limited length of the signature. Once the scanner has passed all four lines along the signature, it is certain that it has read all the necessary markings on the signature and can move on to the next signature. Even though there are more lines used on each signature than the two lines of the Fig. 2 embodiment, the fact that the lines are narrow means that even if they do protrude into the printed face of the book, they would not be regarded as being objectionable.

The apparatus for operating the two systems in accordance with the invention as described above is likely to comprise four main units. The first unit will comprise a conveyor which transports the book block across the scanning head. The conveyor will be equipped with a device for holding the book block and squeezing the book together to a consistent thickness to produce a constant scan in one direction.

The second unit will comprise the scanning head in the form of a television camera. It fits under the conveyor and is connected to the third unit that is a control box. The control box will consist mainly of a single board computer, associated memory and control circuitry. In general it is situated near the conveyor for convenience reasons. This unit has a display to indicate which signature is faulty.

The book is automatically diverted if faulty and a series of identical faults will stop the machine.

An optional visual display unit comprising the fourth unit may be provided so that the books can be seen remotely for alternative or additional inspection.

The device is situated at the out-feed of a gathering machine or the in-feed to a bookbinding machine. The operator makes sure that the first book is correctly gathered and passes it over the unit switched on to the "calibrate" mode. The output resulting from the correct book is recorded in the memory of the micro-processor. The lay-out of marks on subsequent books are compared with the first one and any which are different are diverted into a reject system. These are then checked by the operator for any mis-collation and then corrected.

Various further operator aids may be provided in the system to enable a check on quantity to be kept.

Claims

1. A method of checking book blocks comprising applying to each different signature to be made up into a book block at least two spaced narrow lines extending transversely across the outer side of the fold of the signature, the arrangement of the lines being arranged to be unique to each different signature and carrying out an optical scan of the assembled signatures comprising scanning along each signature in turn and comparing the results of the scan with the scan of a correctly assembled book block to determine whether the block is acceptable or not.

2. A method as claimed in claim 1 wherein each signature is marked with two transverse lines at the outer side of the fold of the signature, the spacing of the lines being unique to each different type of signature to be read by the scanner.

3. A method as claimed in claim 2 wherein one of the lines on each signature is located adjacent one end of the signature and the other line is spaced from that line by an appropriate distance unique to that type of signature.

4. A method as claimed in claim 1 wherein the fold of each signature has a pair of transverse lines spaced apart along the signature by a distance which is common to all signatures and a pair of intermediate lines spaced between the first pair of lines in a unique arrangement for each signature.

5. A method as claimed in claim 4 wherein there are a number of discrete positions between the spaced pair of lines which the further pair of lines may occupy, the positioning of the intermediate lines in various combinations of different positions providing unique arrangements of the lines for each signature.

6. A method of checking book blocks substantially as described with reference to and as illustrated in the accompanying drawing.