Patent ID: 7472975

Claim:
A substrate for an ink jet printing head having ejection energy generation means for generating an ink ejection energy, and a fuse element capable of being blown by passing an electric current therethrough, the substrate comprising: current adjusting means provided in a circuit through which the electric current flows, wherein in a process of blowing the fuse element, the current adjusting means adjusts the electric current so that the electric current continues to flow in the fuse element for a predetermined duration even after a maximum current has flowed through the fuse element, the predetermined duration is longer than a period from a time point when the electric current rises to a time point when the electric current reaches the maximum current, and in the process of blowing the fuse element, the current adjusting means flows an electric current of 30 mA or lower for 2 μs or more after flowing an electric current of 80 mA or higher.