| 摘要 |
The heat absorbing text of a printing machine master on a duplicating drum is placed in contact with a dye coating on a sheet or web and irradiated by a first source of radiation so that portions of dye coating in contact with the heat absorbing text melt and adhere to the heat absorbing text while the remainder of the dye coating remains on the sheet when the same is pulled off the master. During the following revolutions of the duplicating drum, copy sheets are fed while a second source of radiation heats the applied coating on the text of the master before the text reaches the printing line. Shielding means are selectively operated to cover the first and second sources of radiation to prevent coating before printing, and dye transfer during printing, so that selected shielded lines of the master are not printed. In another embodiment, coated narrow and wide webs selectively cooperate with corresponding narrow and wise sections of the master sheet. |
