US 7,296,882 B2 · Ink jet printer performance adjustment

Abstract

An ink jet printer includes an ink supply system and a printhead with nozzles for ejecting ink drops. The printer determines the average size of the ejected ink drops by comparing the number of ink drops ejected in a predetermined time with the quantity of ink delivered through the printers ink supply system during that time. If the determined average ink drop size does not match predetermined ink drop size criteria, the printer adjusts the activation signals for the ink jet nozzles to alter the ink drop size. A solid ink printer determines the quantity of ink delivered through the ink supply system by counting the number of whole or partial ink sticks that pass a predetermined point in the ink supply system. The counter detects a sensing element formed on an external surface of the ink stick. Exemplary detectors include a mechanical arm, or a thermistor to detect a change in the printer melt plate temperature due to a change in the cross sectional area of an ink stick being melted.

Claims22

Dependent claims

In an ink jet printer that ejects ink drops from printhead ink nozzles in response to ink nozzle activation signals, a method of adjusting ink drop size, the method comprising:

sending to printhead ink nozzles first ink nozzle activation signals;
determining a quantity of ink passing a predetermined point in a printer during a specified time period;
determining a number of ink drops ejected from the printhead ink nozzles during the specified time period;
determining a determined size for each ink drop from the quantity of ink passing the predetermined point in the printer and the number of ink drops ejected during the specified time period;
determining if the determined size of each ink drop meets predetermined drop size criteria;
and
if the determined size of each ink drop does not meet predetermined drop size criteria, sending to the printhead ink nozzles second ink nozzle activation signals, wherein the second ink nozzle activation signals are different from the first ink nozzle activation signals.

4 more elements

An ink jet printer comprising:

an ink jet printhead having a plurality of ink jet nozzles;
an ink supply system;
wherein the ink supply system is connected to deliver ink to the ink jet printhead;
an ink measuring system for determining an amount of ink passing through the ink supply system during a predetermined time;
a plurality of ink drop ejectors, each of which is connected to cause one of the ink jet nozzles to selectively eject drops of ink in response to nozzle activation signals;
an activation controller configured to generate nozzle activation signals;
an ink drop counter for determining a number of ink drops ejected from the ink jet nozzles of the printhead during the predetermined time;
and
a control module;
wherein the control module is operatively connected to receive information from the ink drop counter and the ink measuring system;
wherein the control module is configured to determine an average size of the ink drops ejected from the ink jet nozzles during the predetermined time;
wherein the control module is configured to determine whether the determined average size of the ink drops meets predetermined drop size criteria;
and
wherein the control module is configured to cause the activation controller to alter the nozzle activation signals if the determined average size of the ink drops does not meet predetermined drop size criteria.

11 more elements

A controller for an ink jet printer in which ink nozzle activation signals selectively cause ink jet nozzles to eject ink drops, the controller comprising:

an information input configured to receive ink quantity information indicative of a quantity of ink passing through an ink supply system during a first predetermined time period, and for receiving ink drop information indicative of a number of ink drops ejected by ink jet nozzles in the first predetermined time period;
a calculation element configured to calculate a calculated average size for the ink drops ejected by the ink jet nozzles during the first predetermined time period, to determine if the calculated average ink drop size meets predetermined ink drop size criteria, and to determine whether the number of ink drops ejected by the ink jet nozzles in the first predetermined time period and the quantity of ink passing through the ink supply system during the first predetermined time period meet predetermined criteria;
a compensation element configured to change ink nozzle activation signals sent to the ink jet nozzles to eject ink drops from the nozzles of a ink jet printer if the number of ink drops ejected by the ink jet nozzles in the first predetermined time period and the quantity of ink passing through an ink supply system during the first predetermined time period do not meet the predetermined criteria.

Dependencies are inferred from the claim text.

Ink jet printer performance adjustment

Life of this patent

Ink jet printer performance adjustment

Life of this patent

Abstract

Claims22