Synchronization Detector for Magnetic Card Reader
Original Publication Date: 1985-Jan-01
Included in the Prior Art Database: 2005-Feb-18
In a cash card reader in which a card is manually driven through the magnetic head for reading of data recorded in the magnetic stripe thereon in the F2F form, a circuit is provided for sensing the synchronized condition for the card reading, that is, the substantially even card moving condition for enabling the search for SOD (Start of Data) signal, by checking the leading synchronizing signals initially read from the card to detect a predetermined number of successive signals with substantially even periods. This prevents the uneven synchronizing signals due to the instability of the card speed at the start of the movement from being taken for the SOD signal. Fig. 1 shows the circuit in block diagram, and Fig. 2 is a timing chart for signals in the circuit. The oscillator (OSC) continuously generates reference pulses.