DEVICE FOR SCANNING PICTURES

摘要

An optical device for scanning pictures contains a photoelectric transducer (1), which is mounted on the carriage of a mechanical printer, the output of which is connected to a processing circuit via an interface (8) of the printer. It is characterised by a series circuit, connected to the output of the photoelectric transducer (1), of a matching block (2), an amplifier (3) and an analog/digital converter (4) and by a first change-over switch (5) and a switch (6) for disconnecting the corresponding printing-head hammer, the outputs of the change-over switch (5) being connected to terminals of the interface (8) of the printer for transmitting the printer status, a first group of the switching inputs of the change-over switch (5) being connected to the lines for transmitting the status of the printer and a second group of the switching inputs of the change-over switch (5) being connected to the corresponding outputs of the analog/digital converter (4), the control input of which is connected to the STROB terminal of the interface (8) of the printer,the SELECT terminal of the interface (8) of the printer being connected to the line for controlling the first change-over switch (5) and to the line for controlling the switch (6) for disconnecting the corresponding printing-head hammer, the synchronisation output of which is connected to the corresponding input of the second group of switching inputs of the change-over switch (5) and the switching terminals of the switch (6) for disconnecting the corresponding printing-head hammer are connected into the line for transmitting the current pulse from the printer to the corresponding hammer. The device can be switched back and forth between read and printing operation without reequipment.