METHOD OF READING AND PRINTING FOR ELECTRONIC BLACKBOARD

• Main Authors: MORI GORO, ISHII TATSUO, SHIGETA SEIICHI
• Format: Patent
• Language: English
• Published: 15.07.1987
• Subjects: ACCESSORIES FOR WRITING OR DRAWING; ARTICLES FOR WRITING OR DRAWING UPON; BUREAU ACCESSORIES; 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; WRITING OR DRAWING IMPLEMENTS

PURPOSE:To reproduce the contrast of a picture in one dot of a thermal head by allowing a CCD image sensor side to decompose one picture element of a picture into plural picture elements for reading and allowing the thermal head side to divide the read picture element data as above into each picture element group and printing overlappingly them on one line. CONSTITUTION:A picture data read by a CCD image sensor 11 is digitized by an A/D conversion circuit 14 and binary-coded in white/black picture by a digital comparator 16. The data is converted into an 8-bit parallel data by a serial/parallel conversion circuit 17 and inputted to a thermal head 12. On the other hand, a clock pulse generator 20 inputs directly a clock to the CCD image sensor 11 and inputs a clock subject to 1/3 frequency division via a ternary counter 12 to the thermal head 12. Every time the CCD image sensor 11 reads one line of the picture, since the thermal head 12 applies three times overlapped print on one line by 1/3 pulse width, the intermediate tone is reproduced.