| Patent application number | Description | Published |
|---|
| 20090213156 | Printing apparatus having line-type ink jet head and method of printing images by line-type ink jet head - A printing apparatus is provided with a line-type ink jet head having a plurality of blocks on each of which a set of ink ejection elements are arranged. In the printing apparatus, a drive voltage signal is accompanied with a prepulse to be applied to each ink ejection element. Particularly, drive signal adjustment values are stored in association with each block. The drive voltage signal is generated for each set of ink ejection elements with reference to the drive signal adjustment values in association with the block on which the each set of ink ejection elements are arranged. By this configuration, it is possible to reduce the differential density between the image portion printed by the imperfect block having misaligned nozzles and the image portion printed by the normal block having nozzles arranged in their correct positions throughout the density range. | 08-27-2009 |
| 20090289976 | Ink jet printer having ink maintenance system - An ink jet printer performs a print process by ejecting ink for each of a plurality of ink colors. When a predetermined first circulation time elapses after starting the ink circulation, an ink agitating operation drive signal generation unit applies an ink agitating operation drive signal to an ink ejecting unit set operable to eject an ink, which has a predetermined nature, for a first ink agitating operation time in a first period, and applies the ink agitating operation drive signal to an ink ejecting unit set operable to eject an ink, which has not the predetermined nature, for a second ink agitating operation time in a second period which is shorter than the first period. It is therefore possible to perform maintenance effectively in advance of starting the print process in accordance with the nature of ink. | 11-26-2009 |
| 20100013883 | Ink circulation type inkjet printer - An ink circulation type inkjet printer includes a maintenance controller configured to: (1) allow a maintenance mechanism to execute maintenance processing for a plurality of inkjet heads before a present printing job under three conditions that: (c1) an elapsed time from a last printing job to a present printing job is less than a first reference time; (c2) the present printing job requests for ejecting ink from unused nozzles of multiple nozzles of the plurality of inkjet heads in the last printing job; (c3) the elapsed time is more than a second reference time; (2) allow the ink circulation type inkjet printer to perform the present printing job without the maintenance processing for the plurality of inkjet heads when the elapsed time is less than the predetermined second reference time. | 01-21-2010 |
| 20100321438 | IMAGE FORMER - An ink discharge unit includes a plurality of nozzles and corresponding ink propelling mechanisms for the nozzles, and configured to discharge ink through the nozzles in accordance with drive signals to drive the ink propelling mechanisms, an ink temperature sensor is adapted to measure a temperature of ink at the ink discharge unit, and a negative-pressure controller is configured to control negative pressures acting on menisci formed in vicinities of the nozzles by surface tension of ink at the ink discharge unit, wherein the negative-pressure controller is configured to work with a discharge of ink by the ink discharge unit, operating for a measured temperature of ink by the ink temperature sensor equal to or higher than a first reference, to control the negative pressures to a first value, and for a measured temperature of ink by the ink temperature sensor lower than the first reference, to control the negative pressures to a second value which is lower than the first value. | 12-23-2010 |
| 20110074840 | PRINTING MACHINE - A duplex printing machine | 03-31-2011 |
| 20110211002 | DROPLET PROPELLING DEVICE - A drive pulse P | 09-01-2011 |
| 20120013659 | INK JET PRINTER HAVING INK MAINTENANCE SYSTEM - An ink jet printer performs a print process by ejecting ink for each of a plurality of ink colors. When a predetermined first circulation time elapses after starting the ink circulation, an ink agitating operation drive signal generation unit applies an ink agitating operation drive signal to an ink ejecting unit set operable to eject an ink, which has a predetermined nature, for a first ink agitating operation time in a first period, and applies the ink agitating operation drive signal to an ink ejecting unit set operable to eject an ink, which has not the predetermined nature, for a second ink agitating operation time in a second period which is shorter than the first period. It is therefore possible to perform maintenance effectively in advance of starting the print process in accordance with the nature of ink. | 01-19-2012 |
| 20120019590 | INKJET PRINTER AND INKJET HEAD MAINTENANCE METHOD - An inkjet printer | 01-26-2012 |
