GB2034941A - Information storage and retrieval system - Google Patents

Abstract

Hierarchical microfilm information storage system includes a camera producing microfilm copies of documents. The microfilm is stored in a library and in allocated two address, one in the library and another in a computer store. The computer is programmed to control a microfilm reading scanner and a microfiche writing scanner to produce microfiche copies of selected frames in the library. The microfiche may be updated by direct copy of documents or by overlaying part of microfilm frame with a document. The microfiche is stored in a rapid access microfiche store. The microfiche store contains information selected from the library and grouped together on the basis of subject matter index.

Description

SPECIFICATION Information storage and retrieval system This invention relates to the storage and retrieval of information by means of a system which employs microfilm. The object of the invention is to retain the benefits of a microfilm storage system whilst permitting the selective retrieval and revision of information.

According to the invention, there is provided an information storage system in which source documents are scanned to provide microfilm which is stored in a microfilm library and, at the time of filming, each document is allocated two addresses, one for the library and one for a store in the computer, and a further store, of more rapid access than the library is produced by means of a scanner of selected frames in the library under the control of the computer.

The computer is preferably programmed in accordance with indexing of the library and enables access to a frame or frames in the library under the control of a search programme; the system preferably includes an electronic reader, such as a video scanner, disposed for reading a selected frame of the library; a writing scanner, such as a writing cathode ray tube, which can receive a video signal from the reader to produce frames for the said further store and a display terminal which can display a selected frame or frames stored for the time being in the said further store.

There follows a more particular explanation of the nature and purposes of the present invention with reference to the accompanying Figs. 1 to 8.

Microfilm is a permanent store which cannot easily be changed or destroyed. However, according to ordinary microfilming techniques it is difficult to remove information from a film store or to add information to it. Computer systems are particularly versatile in index control, updating and the removal of redundant information. One example of a computer storage system includes a main library, constituted by a magnetic tape into which tapes may be loaded by a user. As may be seen in Fig. 1, from such a library a random access rapid retrieval store may be raised. The store is usually magnetic disc though magnetic tape may be used. The contents of the latter store may be continually revised and in general comprise the variable information in the storage system.An essential feature of a rapid retrieval store such as a magnetic disc is that information is stored in it at random and requires a search for its retrieval. There are many occasions when information is required according to its subject and in computer systems a floppy disc or tape cassette may be used for this purpose, each disc or cassette containing all the information relating to a particular subject required by a user. Using the computer, information from each store can be displayed on a visual display unit, which usually may be used to correct or alter displayed information and, in conjunction with the computer, to relay the altered information back to the random access store.This latter facility has not so far been feasible when microfilm storage has been employed: it has been the practice to store information in microfilm systems according to subjects but the practice is not compatible with rapid retrieval.

Microfilm stores information page by page, whereas a computer stores individual characters. The present invention provides for the manipulation of pages in much the same way as a computer manipulates characters, although in practice the time scale is rather longer than that which might be achieved for the storage of individual characters.

It is intended, assuming that a filing system is already in existence, that documents should be filmed on to 16 mm film in chronological order, there being a data entry at the time of filming such that for each document there is a physical address on the film and a computer address. The 16 mm film constitutes a microfilm library of source documents; it is the equivalent of the magnetic tape library indicated in Fig. 1. At least some of the documents which are "stored" in the film library may required retrieval or alteration quickly and frequently. A further representation of each such document is stored in a random acess store which may be constituted by a carousel of microfiche frames or a 105mm fuilm store, untrastrip or other microform.

Such a random access store may be produced automatically, under the control of the computer, from the film library of source documents. It is possible to create a 500 frame fiche in less than 15 mintues and to refilm a standard carousel in two to three weeks instead of the nine months which is typical at present.

It is intended that a user should be able to obtain subject files only on request and that they be formed only at such a time. The computer controls the index of the main source document library and already has the index organised into subjects according to the programme in use. When a user demands a subject, he may receive this in fiche form in a matter of minutes, depending on the size of the file. For example, an optically readable fiche of 98 frames might be produced. The output of the system may be a display terminal which in accordance with present practice, may permit updated refilming to be undertaken with the aid of the computer.

The source document file may be in the specific form of 16 mm cassettes containing, typically, 80,000 frames. In order to produce a subject file, the cassettes may be loaded into an electronic reader, which may consist of a video scanner of, 3,000 line resolution; such a resolution is feasible because the video scanner need not operate at the frame rates associated with television broadcasting. Under the control of the computer, the film may be moved to the desired frame which is scanned in, typically, 100 ms. The video signal is passed to a writing cathode ray tube in a camera system. the displayed picture being filmed onto whichever microform is applicable. The formation of new film in the random acess store is governed almost entirely by the time taken to find each relevant frame in the main library.

It is readily possible to provide the following features; (1) the complete control of the system by computer from filming to retrieval; t2) the updating of data in the random access store at virtually any time; and (3) the easy removal of redundant information from the rapid access store.

Figs. 3 to 6 illustrate various developments of the system; and in particular Fig. 3 illustrates the system in general, Figs. 4 and 5 the production of the random access store and Fig. 6 the production of a master film library.

Figs. 7 and 8 illustrate the compilation of the film library and the retrieval and updating system associated with the film library respectively.

In the system shown in Fig. 7, documents (hard copy) 1 are reproduced either by a 16 mm microfilm camera 2 or by a rapid processor camera 3 or by a flow camera 4 or by a high speed flow camera 5 or by means of a digitising flow camera 6, a modem 7 and a microfilm reproducer 8. Data entry of both computer address and physical address of each document is performed by means of a keyboard at the time of filming; it may be verified later against the actual film in the system store.

The microfilm 9 produced by whichever means is preferred may be verified and edited at a station 10 before it enters the source document film library 11. The microfilm is also scanned by a scanner 12, which is associated with the reader display terminal 13 and a computer, namely the central processing unit 14, which stores the relevant addresses.

The system shown in Fig. 8 includes the film library 11 and the central processing unit 14 of previous mention; for convenience the reader display terminal 13, which may institute such programmes by the central processing unit 14, is not repeated in Fig. 8.

The processor unit 14 controls the library 11 and a video scanner 15 to provide readout from the library of selected frames. This scanner 15 may provide data for reproduction by any of the two microfiche reproducers 16 and 17 or the microfilm reproducer 18. The reproducer 16 provides microfiches for a microfiche storage and retrieval unit 19, which includes a display in the form of a visual display unit. The reproducer 17 and the microfilm reproducer 18 provide an input to a manual microfiche store 20 and a manual microfilm store 21 respectively.

Microfilm for the library 11 may be produced with the aid of microfilm reproducer 22 scanning selected microfiches from the unit 19; the reproducer 22 may also derive an input from hard copy documents 23 by way of a video scanner 24. The ensuing image may be the result of overlaid pictures from unit 1 9 and the hard copy via the video scanner 24.

The scanner 15 may provide an input which enables hard copy or microfilm to be reproduced from a source document in the film library 11. For this purpose a video digital encoder and decoder 25, receiving an appropriate input from the scanner 15 is coupled by way of a modem 26 either to a facsimile producer 27 to produce hard copy 28 or to a microfilm reproducer 29 to produce 16 mm microfilm 30.

Claims (2)

1. An information storage system in which source documents are scanned to provide microfilm which is stored in a microfilm library and, at the time of filming, each document is allocated two addresses, one for the film library and one for a store in a computer, and wherein a further store, of more rapid access than the library, and comprising selected frames from the film library, is produced by means of scanners under the control of the computer.

2. A system according to claim 1 in which the computer is programmed in accordance with indexing of the library to enable access to a frame or frames in the library under the control of a search programme, the system further comprising an electronic reader disposed for reading a selected frame of the library, a writing scanner which can receive a video signal from said reader so as to produce frames for the said further store, and a display terminal which can display a selected frame or frames stored for the time being in the said further store.