Print media edge printing

• US 20050179758A1
• Filed: 01/13/2005
• Published: 08/18/2005
• Est. Priority Date: 01/13/2004
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Rufes, Ezequiel Jordi, Gonzalez, Daniel, Campillo, Alejandro, Serra, Marc, Cercos, Angel, Rodriguez, Servando, Veciana, Joaquim, Hinojosa, Antonio
• Granted Patent: US 7,543,927 B2
• Time in Patent Office: Days
• US Class Current: 347/101
• CPC Class Codes: B41J 11/0065 Means for printing without leaving a margin on at least one edge of the copy material, e.g. edge-to-edge printing
• CPC Class Codes: B41J 11/0095 Detecting means for copy material, e.g. for detecting or sensing presence of copy material or its leading or trailing end

Abstract

In printing apparatus, when printing near the end of a print media with a printhead having nozzles, a controller causes a print drive to produce a large print media advance movement together with the use of a different group of nozzles from that used for the rest of the print media. This avoids printing artefacts as the print media leaves a pinch in a media feed. In one embodiment the number of nozzles used for printing in the end region is reduced, and the center of the group of nozzles is simultaneously shifted in the direction of print media advance. The size of the print media advance is also changed in the end region. The printing mask used is also changed.

Claims

1. A method of printing on a print media using nozzles in a printhead, the print media having an end and being advanced past the printhead by print media feed means in a print media advance direction, wherein, when said end of the media is released by the feed means, the method comprises the steps of causing the media to undertake a relatively large media advance movement and correspondingly using different nozzles of the printhead to print on the media.

2. A method according to claim 1, wherein the print media includes a main region and an end region at said end, and printing occurs on said main region using a first group of adjacent ones of said nozzles extending in a direction parallel to the direction of media advance, and printing occurs on said end region using a second group of adjacent ones of said nozzles extending in said direction.

3. A method according to claim 2, wherein the centre of said second group of adjacent nozzles used on said end region is shifted in the direction of media advance relative to the centre of said first group of adjacent nozzles used on the main region.

4. A method according to claim 3, wherein the size of said relatively large media advance movement is substantially equal to the distance between the centres of said first and second groups of adjacent nozzles.

5. A method according to claim 2, wherein, around a transition between said main region and said end region, the number of nozzles used for printing is changed, so that fewer nozzles are used in said end region than in said main region.

6. A method according to claim 2, wherein in said main and end regions, the print media undergoes an advance movement between each application of ink by the printhead nozzles, and around a transition between said main region and said end region, the size of the print media advance movement is changed so that the print media advance movement in said end region is smaller than the print media advance movement in said main region.

7. A method according to claim 6, wherein different printing masks are used around the transition between said main region and said end region.

8. A method according to claim 2, wherein, around a transition between said main region and said end region, in a first phase the swath height is gradually reduced while the size of the print media advance is maintained at a first reduced value, and in a second phase the swath height is maintained at a reduced value while the size of the print media advance is maintained at a second, further reduced value.

9. A method according to claim 1, wherein the feed means comprises a feed roller element and an associated pinch element defining a pinch therebetween and the release of the media by the feed means is constituted by the print media leaving said pinch.

10. A printing apparatus comprising a printhead arranged to print ink from a first part thereof onto a print media in a printing zone, a media drive for feeding the print media through said printing apparatus in a media advance direction, and a detector for sensing the approach to said printing zone of an end region of the print media, wherein a controller is provided, in response to said detector, to cause the drive to advance the print media by a relatively large advance movement, and to cause the printhead to print ink from a second part thereof, said second part being shifted, relative to the first part along the printhead in the direction of media advance.

11. A method of printing by a printhead in and approaching the end region of a print media wherein in a first phase the swath height is gradually reduced while the size of the print media advance is maintained at a first reduced value, and in a second phase the swath height is maintained at a reduced value while the size of the print media advance is maintained at a second, further reduced value.

12. A method of printing on a print media using a printhead comprising an array of ink nozzles, the print media including a main region and an end region, wherein printing occurs on said main region using a first group of adjacent ones of said nozzles and printing occurs in said end region using a second group of adjacent ones of said nozzles, the centre of said second group of nozzles being shifted along the array of nozzles relative to the centre of said first group of nozzles.

13. A printing apparatus comprising a printhead arranged to print ink on a print media, a print media drive, said print media drive causing a print media to undertake successive advance movements relative to the printhead, and a detector, said detector sensing an end region of an advancing print media, the arrangement being such that, when said detector detects the approach of a said end region, said print media drive is arranged to cause the print media to undertake relatively small advance movements.