Patent ID: 6712437
Filing Date: 2004-03-30
Classification: B41J

Abstract:
A substrate for a printhead comprising:a printing element for discharging ink and printing; a logic circuit for outputting a logic signal for driving said printing element; transistors for driving said printing element by a signal based on the logic signal outputted from said logic circuit; and a voltage converting circuit, which has a plurality of inverters disposed between said logic circuit and gate electrodes of said transistors, for converting the voltage of the logic signal by utilizing a predetermined power-supply voltage, wherein one of said plurality of inverters, which is provided at an initial stage of said voltage converting circuit, comprises a PMOS transistor and an NMOS transistor, and a transistor structure of said PMOS transistor and said NMOS transistor is adjusted in such a manner that the threshold voltage of said initial stage inverter becomes a voltage which is less than one-half the predetermined power-supply voltage and which is less than a power-supply voltage of the logic signal outputted from said logic circuit.