MULTIVALUED THERMAL PRINTER

• Main Authors: MIKAMI TOMOHISA, NAKA TOSHIYA
• Format: Patent
• Language: English
• Published: 21.06.1988
• Subjects: CORRECTION OF TYPOGRAPHICAL ERRORS; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; LINING MACHINES; PERFORMING OPERATIONS; PICTORIAL COMMUNICATION, e.g. TELEVISION; PRINTING; SELECTIVE PRINTING MECHANISMS; STAMPS; TRANSPORTING; TYPEWRITERS

PURPOSE:To eliminate noises and prevent moire fringe, ununiformity in hue or the like from being generated, by varying the recording timing by a predetermined amount for each of primary colors, and ensuring that the sum total of variations of a predetermined number of successive recording picture elements for arbitrary recording picture elements is less than a predetermined value, at the time of density gradation recording. CONSTITUTION:A data latch part 11a in a gradation data converting part 11 reads gradation data on each picture element in response to a line start signal (generated with a predetermined timing), and latches the gradation data. The line start signal is sent also to a variable delaying part 13c, whereby it is converted into a recording timing strobe signal for driving a head for each recording picture element, according to an arbitrary timing generated by a random number generating part 13a. A pulse generator 12a in an imagerecording part 12 generates pulses with a duration optimum for driving heat generating elements 12c on the basis of output from a driving pulse duration memory (ROM) 11b and an arbitrary recording timing outputted from the delaying part 13c. Noises in images to be recorded are eliminated by an effect similar to the effect of screen angle setting, and moire fringe, ununiformity in hue or the like can be securely prevented from being generated.