| US 7,600,836 B2 | ||
| Printhead driving method for printhead with reference voltage source, voltage divider, and differential amplifier | ||
| Kazunori Masuda, Saitama (Japan) | ||
| Assigned to Canon Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Dec. 29, 2006, as Appl. No. 11/617,867. | ||
| Application 11/617867 is a division of application No. 10/896074, filed on Jul. 22, 2004, granted, now 7,290,848. | ||
| Claims priority of application No. 2003-287139 (JP), filed on Aug. 05, 2003. | ||
| Prior Publication US 2007/0109335 A1, May 17, 2007 | ||
| Int. Cl. B41J 29/38 (2006.01) | ||
| U.S. Cl. 347—10 | 2 Claims |

| 1. A printhead driving method for driving an inkjet printhead having plural printing elements, a reference voltage source
capable of outputting a reference voltage and a non-volatile memory for storing data indicating a pulse width of a drive signal
for driving the plural printing elements, wherein the inkjet printhead is mounted to a printing apparatus or a printhead test
device, the inkjet printhead further comprising a voltage dividing circuit for dividing a voltage supplied from the printing
apparatus or the printhead test device, and a differential amplifier for comparing the voltage divided by the voltage dividing
circuit with the reference voltage from the reference voltage source and outputting a signal based on a result of the comparison,
the printing apparatus and the printhead test device each including a power supply circuit having a similar construction,
and each power supply circuit is operable in a manner such that a difference between the divided voltage and the reference
voltage is eliminated, said method comprising the steps of:
mounting the inkjet printhead to the printhead test device;
supplying a voltage based on the signal outputted from the differential amplifier and a drive signal having a pulse width
based on data set in the printhead test device to the inkjet printhead;
measuring an ink amount discharged from the inkjet printhead;
storing the data indicating the pulse width with which the drive signal is used for driving the inkjet printhead into the
non-volatile memory;
removing the inkjet printhead from the printhead test device and mounting the printhead to the printing apparatus; and
supplying the voltage based on the signal outputted from the differential amplifier and the drive signal based on the data
indicating the pulse width stored in the non-volatile memory to the inkjet printhead.
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