Head substrate, printhead, head cartridge, printing apparatus, and method for inputting/outputting information

Abstract

An object of this invention is to provide a safe and reliable head substrate having a fuse ROM without increasing the substrate size. To achieve the object, a head substrate includes a plurality of printing elements for printing, first driving elements which drive the printing elements, a fuse ROM which stores information, a second driving element which drives the fuse ROM, input device for inputting a printing signal to cause the plurality of printing elements to print and a block selection signal to time-divisionally drive the printing elements, selective driving device for selectively driving the first driving elements on the basis of the input printing signal and block selection signal, a first pad which applies a first voltage to the fuse ROM to write information, and a second pad which applies a second voltage to read out the information from the fuse ROM. In order to selectively drive the second driving element to operate the fuse ROM, the second driving element connects to the selective driving device, and the fuse ROM is selectively operative on the basis of the signals input from the input device.