초록 ▼

A method and system for detecting a nonfunctional element in an ink jet printhead is disclosed. The ink jet printer system includes: a switching power supply, coupled to the inkjet printhead, for supplying power to the printhead; an output capacitor, coupled to an output of the switching power suppl

A method and system for detecting a nonfunctional element in an ink jet printhead is disclosed. The ink jet printer system includes: a switching power supply, coupled to the inkjet printhead, for supplying power to the printhead; an output capacitor, coupled to an output of the switching power supply, for storing a dc voltage therein; a bleed resistor, coupled in parallel to the output capacitor, for discharging current from the output capacitor; an output shifting circuit, coupled to the switching power supply, for shifting the dc voltage level across the output capacitor between a low state and a high state; and a sensor, coupled to the output of the switching power supply, for detecting when the switching power supply is switching, wherein an element of the printhead is tested by measuring a test current discharging from the output capacitor when the element is activated and comparing the measured test current with a reference current which discharges from the output capacitor through the bleed resistor. The method includes: supplying regulated power to the printhead; storing the regulated power in a capacitor so as to provide a dc voltage across the capacitor; shifting the dc voltage level stored in the capacitor between a low state and a high state; measuring a test current discharging from the capacitor when an element of the printhead is activated; measuring a reference current discharging from the capacitor through a bleed resistor, when no elements of the printhead are activated; and comparing the measured test current with the reference current.

대표청구항 ▼

[What is claimed is:] [1.]a switching power supply, coupled to the inkjet printhead, for supplying power to the printhead;an output capacitor, coupled to an output of the switching power supply, for storing a dc voltage therein;a bleed resistor, coupled in parallel to the output capacitor, for disch

[What is claimed is:] [1.]a switching power supply, coupled to the inkjet printhead, for supplying power to the printhead;an output capacitor, coupled to an output of the switching power supply, for storing a dc voltage therein;a bleed resistor, coupled in parallel to the output capacitor, for discharging current from the output capacitor;an output shifting circuit, coupled to the switching power supply, for shifting the dc voltage level across the output capacitor between a low state and a high state; anda sensor, coupled to the output of the switching power supply, for detecting when the switching power supply is switching, wherein an element of the printhead is tested by measuring a test current discharging from the output capacitor when the element is activated and comparing the measured test current with a reference current which discharges from the output capacitor through the bleed resistor.