Abstract: A thermal drop-on-demand ink jet print head in which thermal cross-talk problems are eliminated by providing heat shield members in the space between each of the heater elements. The heat shield members comprise metal fingers attached to either the common heater electrode or one of the control electrodes. The heat shield members enhance flow of heat into the substrate to thereby minimize thermal cross-talk among adjacent channels.

Abstract: Composer method and apparatus are disclosed in which human readable representations of characters are typed on the first part of a page and are thereafter typed on a second part of the page in the machine readable form. Key stroke signals generated by the typewriter keyboard are stored in a memory prior to being applied to access corresponding type ball positioning signals within a table to print the characters using a conventional type ball on the first portion of the page. Thereafter, the conventional type ball is replaced by a special type ball and the key stroke signals stored in the memory are used to access corresponding ones of a different set of type ball positioning signals within a second memory to enable the special type ball to type optically readable binary coded representations of the characters on the second part of the page.