A method and apparatus for erasing printed data from a rewritable card

摘要

In a rewritable card read/write apparatus including a printing thermal head (11) for printing data thermally and a transporting mechanism for feeding a rewritable card (19) forwardly and backwardly so that the rewritable card (19) can pass by the thermal head (11), a method which allows the printed data to be erased within a short time with the thermal head (11) itself. A columnwise printed data erasing range (18) of a printed data area is designated for the card (19) inserted into the apparatus. the thermal head (11) is electrically energized successively at least in two serial cycles by changing over electric energy level at least from a first electric energy level in a first cycle to a second electric energy level in a second cycle. The first electric energy level is so set that a columnwise range of the thermal head (11) which corresponds to the printed data erasing range (18) of the card (19) is heated to a relatively high temperature within a temperature range in which no coloration can occur in the printed data area when the rewritable card (19) reaches a position immediately beneath the thermal head (11). The second electric energy level is set lower than the relatively high temperature and validated when the card (19) again reaches the position immediately beneath the thermal head (11) in the second cycle. The transporting mechanism is controlled such that the rewritable card (19) is fed in a forward direction or in a reverse direction so that the rewritable card (19) moves immediately beneath the thermal head (11) from a first rowwise position corresponding to one end of the printed data erasing range (18) to a second rowwise position corresponding to the other end of the printed data erasing range (18) or alternatively from the second rowwise position to the first rowwise position. <IMAGE>