Method of managing printhead assembly defect data and a printhead assembly with defect data

• US 6,454,378 B1
• Filed: 02/15/2000
• Issued: 09/24/2002
• Est. Priority Date: 04/23/1999
• Status: Expired due to Term

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, Lapstun, Paul
• Primary Examiner(s): HALLACHER, CRAIG ALAN
• Application Number:
  US09/505,151
• Time in Patent Office: 952 Days
• Field of Search: 347/19, 347/41, 347/20, 347/13, 347/40, 347/42, 347/43, 400/74
• US Class Current: 347/19
• CPC Class Codes: B41J 11/002 Curing or drying the ink on the copy materials, e.g. by heating or irradiating
• CPC Class Codes: B41J 11/00216 using infrared [IR] radiation or microwaves
• CPC Class Codes: B41J 2/0057 where an intermediate transfer member receives the ink before transferring it on the printing material
• CPC Class Codes: B41J 2/01 Ink jet
• CPC Class Codes: B41J 2/04508 aiming at correcting other parameters
• CPC Class Codes: B41J 2/0451 for detecting failure, e.g. clogging, malfunctioning actuator
• CPC Class Codes: B41J 2/04586 controlling heads of a type not covered by groups B41J2/04575 - B41J2/04585, or of an undefined type
• CPC Class Codes: B41J 2/155 for line printing
• CPC Class Codes: B41J 2/2139 Compensation for malfunctioning nozzles creating dot place or dot size errors generating single droplets or particles on demand by pressure, e.g. electromechanical transducers B41J2/045
• CPC Class Codes: B41J 2202/21 Line printing
• CPC Class Codes: B41J 3/60 for printing on both faces of the printing material
• CPC Class Codes: G06F 13/00 Interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units interface circuits for specific input/output devices G06F3/00 ; multiprogram control therefor G06F9/46; multiprocessor systems G06F15/16
• CPC Class Codes: G06F 15/00 Digital computers in general details G06F1/00 – G06F13/00; Data processing equipment in general
• CPC Class Codes: G06F 3/12 Digital output to print unit , e.g. line printer, chain printer
• CPC Class Codes: G06K 15/00 Arrangements for producing a permanent visual presentation of the output data , e.g. computer output printersprinting or plotting combined with another operation, e.g. with conveying, G06K17/00
• CPC Class Codes: H04N 1/393 Enlarging or reducing

Abstract

A printhead assembly includes a pair of matched printheads, each printhead including a plurality of inkjet nozzles constructed using microelectromechanical techniques. The printheads are matched so that no paired nozzles of the pair of printheads are both defective. Encoded data relating to a defect list is associated with the printheads, the defect list providing data relating to which nozzle of each pair of matched nozzles of the pair of printheads is to be used.

Claims

1. A method of characterising a printhead assembly for a printer, the method including:

matching a pair of pagewidth printheads, each printhead including a plurality of inkjet nozzles constructed using microelectromechanical techniques, such that no corresponding nozzles of the pair of printheads are both defective;

determining which nozzle of a pair is to be used and generating data relating to the nozzle to be used; and

encoding said data and associating said encoded data with the printhead assembly.

2. The method as claimed in claim 1 in which the data relating to the nozzles to be used consists of a list of defective nozzles and the method includes storing the defect list in a manufacturing database.

3. The method as claimed in claim 2 which includes indexing the defect list with an identification device of the assembly.

4. The method as claimed in claim 2 which includes encoding the defect list in a readable format and applying it to a cartridge of the assembly.

5. The method as claimed in claim 4 which includes, when the cartridge is installed in a printer, retrieving the defect list and writing the defect list to a memory means of a printer controller of the printer.

6. A printhead assembly which includes:

pair of matched pagewidth printheads, each printhead including a plurality of inkjet nozzles constructed using microelectromechanical techniques, the printheads being matched so that no paired nozzles of the pair of printheads are both defective; and

encoded data relating to a defect list associated with the printheads, the defect list providing data relating to which nozzle of each pair of matched nozzles of the pair of printheads is to be used.

7. The assembly as claimed in claim 6 in which the defect list is associated with an identification device of the assembly and is stored in a manufacturing database.

8. The assembly as claimed in claim 6 which includes a printhead cartridge, the defect list, in its encoded format, being applied to the cartridge to be readable by a printer when the cartridge is installed in the printer.