Patent ID: 9102146
Filing Date: 2015-08-11
Classification: B41J

Abstract:
1. A printhead substrate comprising: a plurality of printing elements which are assigned to a plurality of groups; a plurality of driving circuits which are arranged in correspondence with the respective groups and drive the printing elements; a first current source configured to generate currents of a plurality of current amounts corresponding to the respective groups; second current sources which are arranged in correspondence with the respective driving circuits and configured to generate currents to be supplied to the printing elements; and setting units configured to generate voltages in accordance with currents generated by the first current source and set currents to be generated by the second current sources based on the voltages, wherein each of the setting units further includes a sample-and-hold circuit configured to sample and hold a voltage generated inside a current mirror circuit including the second current source, wherein each of the setting units further includes a capacitor configured to charge a current flowing through the current mirror circuit, and wherein the sample-and-hold circuit samples and holds a voltage of the capacitor.