Electronic skew adjustment in an ink jet printer

• US 6,588,872 B2
• Filed: 04/06/2001
• Issued: 07/08/2003
• Est. Priority Date: 04/06/2001
• Status: Expired due to Term

• Current Assignee: Funai Electric Co., Ltd. (Funai Electric Holdings Company Limited)
• Original Assignee: Lexmark International Incorporated (Ninestar Corporation)
• Inventors: Anderson, Frank Edward, Zearfoss, Susan Marie, Cook, William Paul, Parish, George Keith
• Primary Examiner(s): TRAN, HUAN HUU
• Application Number:
  US09/827,805
• Publication Number:
  US 20020145640A1
• Time in Patent Office: 823 Days
• Field of Search: 347/9, 347/19, 347/14
• US Class Current: 347/19
• CPC Class Codes: B41J 2/04505 aiming at correcting alignment
• CPC Class Codes: B41J 2/04573 Timing; Delays
• CPC Class Codes: B41J 2/0458 controlling heads based on heating elements forming bubbles
• CPC Class Codes: B41J 2202/17 Readable information on the head

Abstract

A system is described for compensating for misalignments in an ink jet printer having an ink jet print head cartridge that includes a heater chip. The system includes determining alignment adjustment information related to the misalignments in the ink jet printer, loading the alignment adjustment information into a volatile memory device on the heater chip, and accessing the alignment adjustment information from the volatile memory device. The system also includes generating nozzle control signals based at least in part on the alignment adjustment information. The nozzle control signals are selectively provided to resistive heating elements in the heater chip, thereby heating ink in ink chambers adjacent the heating elements and ejecting ink droplets toward a print medium. The timing of the nozzle control signals is adjusted based upon the amount of misalignment in the various components of the printer and print head. The timing adjustments are applied to groups of nozzles so that dots printed by one group are substantially vertically aligned with dots printed by another group, thereby reducing the amount of perceptible skew in the printed output.

Claims

1. A method for compensating for misalignments in an ink jet printer having an ink jet print head cartridge that includes a heater chip, comprising the steps of:

(a) providing a volatile memory device on the heater chip;

(b) determining alignment adjustment information related to the misalignments in the ink jet printer;

(c) loading the alignment adjustment information into the volatile memory device on the heater chip;

(d) accessing the alignment adjustment information from the volatile memory device;

(e) generating nozzle control signals based at least in part on the alignment adjustment information; and

(f) selectively providing the nozzle control signals to resistive heating elements in the heater chip, thereby heating ink in ink chambers adjacent the heating elements and ejecting ink droplets toward a print medium.

2. The method of claim 1 further comprising the steps of:

(f) storing heater chip alignment information in a print head memory device disposed on the ink jet print head cartridge;

(g) storing print head alignment information in a printer memory device disposed in one of the ink jet printer and a host computer;

(h) accessing the heater chip alignment information from the print head memory device;

(i) accessing the print head alignment information from the printer memory device; and

step (a) further comprising determining the alignment adjustment information based at least in part on the heater chip alignment information and the print head alignment information.

3. A method for compensating for misalignments in an ink jet printer having an ink jet print head cartridge that includes a heater chip, comprising the steps of:

(a) determining alignment adjustment information related to the misalignments in the ink jet printer;

(b) loading the alignment adjustment information into a volatile memory device on the heater chip;

(c) accessing the alignment adjustment information from the volatile memory device;

(d) receiving address information;

(e) determining nozzle select information based on the alignment adjustment information and the address information;

(f) receiving print data corresponding to an image to be printed on a print medium;

(g) generating nozzle control signals based at least in part on the nozzle select information and the print data; and

(h) selectively providing the nozzle control signals to resistive heating elements in the heater chip, thereby heating ink in ink chambers adjacent the heating elements and ejecting ink droplets toward a print medium.

4. The method of claim 3 wherein:

step (c) further comprises accessing X number of bits of alignment adjustment data from the volatile memory device;

step (d1) further comprises receiving a first portion of M number of bits of address data, the first portion comprising X number of the M number of bits of address data; and

step (d2) further comprises;

(d21) adding the X bits of the alignment adjustment data to the X bits of the address data to form X bits of sum data;

(d22) receiving a second portion of the M number of bits of address data, the second portion comprising M−

X bits of the address data not included in the first portion; and

(d23) generating the nozzle select information based on the X bits of sum data and the second portion of the address data.

5. The method of claim 3 wherein:

step (c) further comprises accessing X number of bits of alignment adjustment data from the volatile memory device;

step (d1) further comprises receiving a first portion of M number of bits of address data, the first portion comprising X number of the M number of bits of address data; and

step (d2) further comprises;

(d21) determining a difference of the X bits of the alignment adjustment data and the X bits of the address data to form X bits of difference data;

(d22) receiving a second portion of the M number of bits of address data, the second portion comprising M−

X bits of the address data not included in the first portion; and

(d23) generating the nozzle select information based on the X bits of difference data and the second portion of the address data.

6. A method for compensating for misalignments in an ink jet printer having an ink jet print head cartridge that includes a heater chip, comprising the steps of:

(a) storing heater chip alignment information in a print head memory device disposed on the ink jet print head cartridge;

(b) storing print head alignment information in a printer memory device disposed in the ink jet printer;

(c) accessing the heater chip alignment information from the print head memory device;

(d) accessing the print head alignment information from the printer memory device;

(e) determining alignment adjustment information based at least in part on the heater chip alignment information and the print head alignment information;

(f) loading the alignment adjustment information into a heater chip memory device;

(g) accessing the alignment adjustment information from the heater chip memory device;

(h) receiving address information;

(i) determining nozzle select information based on the alignment adjustment information and the address information;

(j) receiving print data corresponding to an image to be printed on a print medium; and

(k) generating nozzle control signals based at least in part on the nozzle select information and the print data; and

(l) selectively providing the nozzle control signals to resistive heating elements in the heater chip, thereby heating ink in ink chambers adjacent the heating elements and ejecting ink droplets toward a print medium.

7. An ink jet printer for forming printed images on a print medium based on print data, the printer comprising:

a carriage movable in a first direction relative to the print medium;

an ink jet print head cartridge including;

a cartridge housing mechanically coupled to the carriage, the cartridge housing oriented with respect to the carriage according to a print head alignment angle;

an ink jet heater chip oriented with respect to the cartridge housing according to a heater chip alignment angle, the ink jet heater chip having;

an array of resistive ink-heating elements; and

a heater chip memory device for receiving alignment adjustment information; and

an array of nozzles corresponding to the array of ink-heating elements through which ink is ejected toward the print medium;

a print head memory device for storing heater chip alignment information related to the heater chip alignment angle;

a printer controller comprising;

a printer memory device for storing print head alignment information related to the print head alignment angle; and

control electronics electrically coupled to the heater chip memory device, the print head memory device, and the printer memory device, the control electronics for accessing the print head memory device to retrieve the heater chip alignment information, for accessing the printer memory device to retrieve the print head alignment information, for determining the alignment adjustment information based at least in part on the heater chip alignment information and the print head alignment information, and for providing the alignment adjustment information to the heater chip memory device.

8. An ink jet printer for forming printed images on a print medium based on print data, the printer comprising:

a carriage movable in a first direction relative to the print medium;

an ink jet print head cartridge including;

a cartridge housing mechanically coupled to the carriage, the cartridge housing oriented with respect to the carriage according to a print head alignment angle;

an ink jet heater chip oriented with respect to the cartridge housing according to a heater chip alignment angle, the ink jet heater chip having;

an array of resistive ink-heating elements;

a heater chip memory device for receiving alignment adjustment information;

a nozzle select logic circuit electrically coupled to the heater chip memory device for receiving the alignment adjustment information, for receiving address information, and for generating nozzle select information based on the alignment adjustment information and the address information; and

a print enable logic circuit electrically coupled to the nozzle select logic circuit for receiving the nozzle select information, for receiving print data, and for generating print enable signals based on the nozzle select information and the print data;

an array of nozzles corresponding to the array of ink-heating elements through which ink is ejected toward the print medium; and

a print head memory device for storing heater chip alignment information related to the heater chip alignment angle; and

a printer controller comprising;

a printer memory device for storing print head alignment information related to the print head alignment angle; and

control electronics electrically coupled to the heater chip memory device, the print head memory device, and the printer memory device, the control electronics for accessing the print head memory device to retrieve the heater chip alignment information, for accessing the printer memory device to retrieve the print head alignment information, for determining the alignment adjustment information based at least in part on the heater chip alignment information and the print head alignment information, and for providing the alignment adjustment information to the heater chip memory device.

9. The ink jet printer of claim 8 wherein the nozzle select logic circuit receives the address information as address data comprising M number of bits, the nozzle select logic circuit further comprising:

an addition logic circuit electrically coupled to the heater chip memory device for receiving therefrom the alignment adjustment information as X number of bits, for receiving a first portion of the address data comprising X of the M bits of address data, and for adding the X bits of the alignment adjustment data to the X bits of the address data to form X bits of sum data; and

a decode logic circuit electrically coupled to the addition logic circuit for receiving therefrom the X bits of sum data, for receiving a second portion of the address data comprising M−

X bits of the address data not included in the first portion, and for generating the nozzle select information based on the X bits of sum data and the M−

X bits of the address data.

10. The ink jet printer of claim 8 wherein the nozzle select logic circuit receives the address information as address data comprising M number of bits, the nozzle select logic circuit further comprising:

a subtraction logic circuit electrically coupled to the heater chip memory device for receiving therefrom the alignment adjustment information as X number of bits, for receiving a first portion of the address data comprising X of the M bits of address data, and for determining a difference of the X bits of the alignment adjustment data and the X bits of the address data to form X bits of difference data; and

a decode logic circuit electrically coupled to the subtraction logic circuit for receiving therefrom the X bits of difference data, for receiving a second portion of the address data comprising M−

X bits of the address data not included in the first portion, and for generating the nozzle select information based on the X bits of difference data and the M−

X bits of the address data.

11. A method for compensating for misalignments in an ink jet printer having an ink jet print head that includes a heater chip, comprising the steps of:

(a) printing a plurality of test images on a test page using the ink jet printer while applying different values of skew adjustment during the printing of each of the test images;

(b) observing the test images printed on the test page;

(c) selecting at least one of the test images as most visually appealing in comparison with other of the test images;

(d) determining at least one optimum value of skew adjustment based on the at least one test image selected in step (c);

(e) storing the at least one optimum value of skew adjustment in a printer memory device;

(f) determining skew adjustment information based at least in part on the optimum value of skew adjustment stored in the printer memory device; and

(g) loading the skew adjustment information into a memory device on the ink jet print head.