Patent GB-1336132-A (GB)
Title: Access-control equipment and item-dispensing systems including
IPC: G07F7/08
Filed: 1969-12-03
Abstract: 1336132 Locks SMITHS INDUSTRIES Ltd 2 Dec 1970 [3 Dec 1969] 59090/69 Heading E2A [Also in Divisions G4 and G5] Access control equipment includes token-receiving means 14 (Figure 1), a plurality of magnetic reading heads 22 for reading magnetic recordings from a received token, and release means 41 operable as a prerequisite to the enabling of access, the arrangement being such that operation of the release means 41 is inhibited if a predetermined relationship is not detected between the recordings read by the different reading heads 22. The reading gaps of different ones of the heads are inclined to one another. The equipment may be used to control entry to a restricted area, the use of a service, or item (e.g. bank note) dispensing. Token. Each customer is issued with a plastics token 10 (Figure 2) bearing embossed characters 11, 12 representing the customer account number and the token expiry date, in both alpha-numeric characters 11 and a twoout-of-five decimal code 12. The token 10 carries darkened areas 15, and a strip of ferromagnetic oxide 24 divided into two tracks 24A, 24B (Figure 4) in which information has been simultaneously magnetically recorded in binarycoded form, as a modulation of an a.c. signal. Two corresponding recordings (GA), (GB) (Figure 3 not reproduced) in the tracks 24A, 24B, when in phase represent a binary "O", and when in antiphase, a binary "I". Each recording may be formed obliquely to correspond with oblique reading gaps 25A, 25B or obliquely and stepped (4A), (4B) (see Figure 5, not reproduced). The magnetically recorded data includes the last date-of-use of the token (which can only be used once a day) and pairs of recordings equal in number (e.g. 50) to the permitted number of token uses. The two data types are recorded at different angles of obliquity. Reading Head Unit. The magnetically recorded data is read by a head unit 22 (Figure 1). Pairs of corresponding recordings of lastdate-of-use (GA), (GB) (Figure 3) are sequentially read by a pair of heads 22A, 22B (see Figure 4). Each head is of straight gap (or stepped straight gap) form. Simultaneously, the "number of uses" recordings are sensed by reading heads (51A), (51B) (see Figure 6, not reproduced) and erased by a straight gap magnetic head (52). The voltage and current to the reading heads (51A), (51B) are limited by diodes (54), (55) (Figure 7, not reproduced) and a fuse (57) respectively, to prevent use of the heads for fraudulent recording.  Operation. As described for a banknote dispenser, an entry slot 14 (Figure 1) is initially blocked by a shutter 16. A photoelectric head 17, on sensing the darkened areas 15 (Figure 2) on a presented token 10, slides the shutter 16 (Figure 1) to permit token insertion. The token is transported by rollers 20 beneath the head unit 22 which reads the magnetically recorded data, and erases a pair of the "number-of-uses" recordings. The data is exexamined for authenticity by a code recognition unit 26, which produces a signal on a line 27 provided (a) the signals from the pair of reading heads 22A, 22B (Figure 4) are of nominally equal magnitudes and/or of greater magnitude than a threshold value and (b) the signals are in-phase or antiphase. The unit 26 (Figure 1) produces a second signal on a line 28 provided (a) there is a signal on line 27 and (b) the data read from the token 10 is earlier than the current date (withdrawal frequency not exceeded). The token 10 is then transported to an imprinter 19 together with a blank 29 from a stack 23. The imprinter 19 records on the blank 29, with a carbon ribbon 30, the data embossed on the token 10; the carbon ribbon 30 is of the "total transfer" type, so providing a second record of the embossings. The imprinted blank passes to a card reader 33, which produces a column-by-column readout, using five photocells, of the expiry date and account number. This data is checked for validity (e.g. against stolen tokens) by a validity-register unit 36, validity being signalled on a line 37. The account number is also fed to an encyphering unit 38 which derives from the number, a secret number. At this stage, an illuminated sign directs the customer to either a code number on a keyboard 42. The code number and derived secret number are compared by a comparison unit 39, which signals a release unit 41 if a predetermined correspondence is noted. The release unit 41 serves to activate a banknote dispenser 40, provided it receives a signal from each of the code recognition unit 26, validity-register unit 36 and comparison unit 39. After dispensing, the token 10 is returned to the customer through the entry slot 14, following updating of the last-date-of-use by the heads 22A, 22B (Figure 4). The token 10 is also returned to the customer, without dispensing, if the withdrawal frequency would otherwise be exceeded; or if the code number and derived secret number do not satisfy the predetermined correspondence. On the other hand, the token 10 is retained by the equipment if not authentic, or invalid, in which case the blank 29 is so stamped. Specifications 1285443, 1285444, 1285445, 1336131, 1336133 and 1336134 are referred to.