Abstract: An object of the present invention is to provide a ribbon feeder to prevent a ribbon from slackening when a sheet is back-fed in a thermal printer. When a ribbon is fed from a ribbon feed roller, resistance is imparted to the rotation of the ribbon feed roller by a first spring. Further, resilient force is stored in a second spring by tension produced when the ribbon is fed from the ribbon feed roller. The ribbon tends to slacken when the sheet is back-fed, such slackening ribbon is rewound by reversely rotating the ribbon feed roller by the stored resilient force.

Abstract: A method of measuring and expressing the unwound amount or residual amount of a web roll, such as carbon film roll or printing paper roll in terms of a unit length of the web roll includes the steps of: starting a count of pulses to be produced by a rotation displacement detecting sensor for each predetermined angle of rotational displacement when the residual amount of the web roll is considered to have been reduced to a predetermined value; and emitting a warning signal when the count reaches a predetermined count number (initially set on the basis of the average value of the amounts of unwinding rotation of the web roll per unit length) during the time when the web roll is unwound and fed by a unit length from the count start time.

Abstract: A dot-matrix printer which operates as a line head printer and is capable of reading line head printer print data and moving head printer print data. A memory stores print data. A series of clock pulses are generated and a shift register reads a portion of the print data from the memory. Upon receipt of a pre-determined clock pulse, the shift register writes the group of print data to a first latch register in a series of latch registers. The print data in each latch register is then written to a succeeding latch register. Upon receipt of a pre-determined clock pulse and in accordance with the print data, heating elements heat specific dot elements in a group of dot elements thus printing an equivalent of one print line. The print sheet is then advanced a distance equivalent to a print line comprising the group of dot elements and the process is repeated as required.

Abstract: A printer having a cutter 6 including: program storage 2 for storing printer control programs such as a data edition program, a printing control program and a cutter control program, where the program storage has a random access memory for storing the predetermined length of each of plural sheet divisions arranged on the web to be cut out, the total length of a printing zone in each of the sheet divisions and a blank distance between adjacent two printing zones of the sheet divisions; and a central processing unit 1 for operating the cutter 6 to cut the sheet division according to the data and the programs read out from the program storage, to cut out a sheet in the predetermined length with a printed zone where the central processing unit 1 precalculates the continued travel length L of the web from a travel reference position, where any predetermined point in the sheet or a subsequent sheet division is placed in a predetermined relative position to the printer after printing of the printed zone, to a travel

Abstract: A thermal head in a thermal printer is biased by a plurality of springs which are provided between the thermal head and stopper of the movable shafts, respectively. The distances between the thermal head and the stoppers are commonly adjusted by a rotating shaft through gears fixed to the rotating shaft and worms formed on the movable shafts, thereby subtly adjusting the thermal head biasing force of the springs in accordance with the condition of a sheet to be used.