Patent ID: 6753687
Filing Date: 2004-06-22
Classification: B41J,G01R

Abstract:
An inspection method for a capacitive load driving unit which comprises a plurality of capacitive loads, a drive circuit for charging and discharging said capacitive loads, a pair of power lines for supplying a drive voltage from an external power source to said drive circuit, and a current reserve circuit for reserving a current required by said drive circuit for charging said capacitive loads, wherein said current reserve circuit includes a capacitor that is charged by the drive voltage from said power lines, and a coupler section that selectively couples the capacitor between the power lines and decouples the capacitor from the power lines, such that the cower lines keen supplying the drive voltage from the external power source to the drive circuit even while the capacitor remains decoupled from the power lines, said method comprising:controlling said drive circuit to sequentially drive said plurality of capacitive loads in a state in which said capacitor is disconnected from said power lines; and detecting an electric change that occurs on said power line upon driving each of said capacitive loads to determine whether a defect is present.