Line printer and printhead moving method of a line printer

Patent metadata

Field	Value
Publication number	US-9566809-B2
Application number	US-201615040625-A
Country	US
Kind code	B2
Filing date	Feb 10, 2016
Priority date	Oct 30, 2013
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

The carriage of a line printer has a head unit that supports a printhead, and a carriage frame that supports the head unit movably up and down. When moving the carriage from a standby position to an opposing position, the carriage is moved while the head unit is held at a up position where the gap to the platen unit is a first distance. The head unit is then lowered at the standby position from the up position to a down position where the platen gap is a second distance that is shorter than the first distance.

First claim

What is claimed is:

1. A line printer comprising:
a printhead including an ink nozzle face;
a platen;
a carriage including a head unit having the printhead and a frame, with a guide channel disposed on the frame, configured to movably support the head unit;
a carriage moving mechanism configured to move the carriage between an opposing position where the printhead is opposite the platen, and a standby position where the printhead is not opposite the platen;
a head unit moving mechanism configured to move the head unit between a first position and a second position, where a gap between the platen and the ink nozzle face in the second position is less than a gap between the platen and the ink nozzle face of the head unit at the first position, when the carriage is at the opposing position, and
a holding frame disposed between the platen and the ink nozzle face of the head unit at the first position,
wherein the guide channel is configured to guide the printhead to a predetermined position such that the printhead does not collide with the holding frame.

2. The line printer described in claim 1 , wherein:
the holding frame comprises a star wheel.

3. The line printer described in claim 1 , wherein:
the head unit moving mechanism is configured to move the head unit in a direction towards the platen when the carriage is at the opposing position, and
the carriage moving mechanism is configured to move the carriage in a direction perpendicular to the direction towards the platen.

4. The line printer described in claim 1 , wherein:
the carriage including an urging member configured to urge the head unit to the first position; and
the head unit moving mechanism moves the head unit in resistance to an urging force of the urging member.

5. The line printer described in claim 1 , wherein:
the second position is a position where the printhead prints to recording paper on the platen.

6. The line printer described in claim 1 , wherein:
the guide mechanism further comprises a guide roller disposed on the head unit, and
the guide roller is inserted in the guide channel.

7. The line printer described in claim 6 , wherein:
the guide roller includes a first guide roller and a second guide roller,
the guide channel extends in the vertical direction, and comprises a first channel section having a first channel width that is the same as a first diameter of the first guide roller, and a second channel section having a second channel width that is greater a second diameter of the second guide roller; and
when the printhead moves between the first position and the second position, the first guide roller moves through the first channel section, and the second guide roller moves through the second channel section.

8. A line printer comprising:
a platen opposite a printhead;
a head unit including the printhead; and
a bearing ball that is disposed in a holding frame, and is configured to contact the head unit and the platen, and sets a gap between the head unit and the platen to a predetermined gap.

9. The line printer described in claim 8 , further comprising:
the holding frame configured to hold the bearing ball rotatably.

10. The line printer described in claim 9 , wherein:
the ball bearing includes at least three bearing balls disposed to mutually separated positions,
wherein the holding frame is configured to hold each of the bearing balls at a position not on a line joining the other two bearing balls.

11. The line printer described in claim 10 , wherein:
the holding frame has a ball holding unit configured to hold the bearing ball; and
the ball holding unit has a through-hole that extends in the vertical direction to which the bearing ball is partially inserted, and a support member that spans the opening on one side of the through-hole in the direction of opposition at the edge of the opening, and can contact the bearing ball from the one side.

12. The line printer described in claim 8 , further comprising:
a moving mechanism that moves the head unit between a first position where the gap is a first distance, and a second position where the gap is a second distance that is shorter than the first distance;
wherein the holding frame is configured to hold the bearing ball in contact with the platen; and
the head unit contacts the bearing ball when the head unit is at the second position.

13. The line printer described in claim 8 , further comprising:
an urging member configured to urge either the head unit or the platen to the other through the bearing ball.

14. The line printer described in claim 8 , further comprising:
a platen support mechanism configured to support the platen movably between a reference position opposite the printhead, and a retracted position that is different from the reference position;
the holding frame is set to a position causing the bearing ball to contact the platen when the platen is at the reference position, and separates the bearing ball from the platen when the platen is at the retracted position.

Assignees

• Seiko Epson Corp

Inventors

• Nagata Norio
• Maekawa Hironori
• Aoki Takashi
• Hirashima Taku

Classifications

• B41J25/304

  Bodily-movable mechanisms for print heads or carriages movable towards or from paper surface · CPC title

• B41J25/3084

  by means of a spacer contacting the matter to be printed · CPC title

• B41J2/16588

  Print heads movable towards the cleaning unit · CPC title

• B41J25/34 Primary

  Bodily-changeable print heads or carriages · CPC title

• B41J25/001 Primary

  Mechanisms for bodily moving print heads or carriages parallel to the paper surface · CPC title