Patent Application
20070002094
This application claims priority under 35 U.S.C. ยง119(a) from Korean Patent Application No. 2005-59668, filed on Jul. 4, 2005, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present general inventive concept relates to an inkjet image forming apparatus, and more particularly, to a print head wiper to wipe nozzles of a print head, and an inkjet image forming apparatus including the print head wiper.
2. Description of the Related Art
Generally, inkjet image forming apparatuses form an image on a printing medium by firing ink from a print head onto the printing medium. An inkjet image forming apparatus can be classified based on a type of the print head used in the apparatus. A shuttle type print head, as it moves back and forth in the width direction of a printing medium, fires ink onto the printing medium. An array type print head includes a plurality of nozzles arranged across the width of the printing medium. Since the array type print head forms an image an entire line at a time by selectively firing ink from its nozzles, the array type print head can print images more rapidly than the shuttle type print head.
Meanwhile, to keep optimal conditions of the ink firing from the nozzles, the inkjet image forming apparatus carries out maintenance during a standby mode. The maintenance, for example, includes spitting a small amount of ink to prevent the nozzles from clogging by dust, dirt, sticking of the ink, etc, and wiping droplets of ink around the nozzles to prevent distortion of the ink firing.
For the maintenance, a print head wiper is required. Unlike the shuttle type print head, the array type print head is fixed. Therefore, the inkjet image forming apparatus including the array type print head requires a mechanism for moving the print head wiper.
The present general inventive concept provides a print head wiper, an inkjet image forming apparatus including the print head wiper, and a method of maintaining the inkjet image forming apparatus, the print head wiper being designed to operate reliably, have a simple structure, and occupy less space.
The present general inventive concept invention also provides a print head wiper to wipe a nozzle surface of a print head that includes nozzles to fire ink, and an inkjet image forming apparatus including the print head wiper.
Additional aspects and advantages of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.
The foregoing and/or other aspects and utilities of the present general inventive concept may be achieved by providing a print head wiper, including a first gear rotatable in both clockwise and counterclockwise directions, a second gear to engage with the first gear, the second gear being rotatable around the first gear, a cleaning roller fixed to the second gear to wipe a nozzle surface of a print head, and a link arm to connect the first gear and the second gear, wherein when the first gear is rotated, the second gear and the cleaning roller revolve in an upward direction around the first gear by a frictional force between the first gear and the link arm until the cleaning roller contacts the nozzle surface, and when the cleaning roller contacts the nozzle surface, the second gear and the cleaning roller rotate around an axis of the second gear by a rotational force of the first gear to wipe the nozzle surface.
The cleaning roller may include an outer layer formed of porous resin to facilitate absorption of the ink by the outer layer.
The cleaning roller may include an outer layer having an elliptical cross section.
The cleaning roller may include an internal heater to evaporate ink absorbed into an outer layer of the cleaning roller.
The print head wiper may further include first washers interposed between the link arm and the first gear to maintain friction between the link arm and the first gear, and second washers interposed between the link arm and the second gear to maintain friction between the link arm and the second gear.
The print head wiper may further include a cleaning solution tank containing a cleaning solution to clean the cleaning roller.
The print head wiper may further include a cleaning roller pressing part located in the cleaning solution tank to press the cleaning roller to facilitate the cleaning of the cleaning roller.
The print head may be an array type print head including the nozzle surface, the nozzle surface having a plurality of nozzles across a width of a printing medium, and the cleaning roller may have a length corresponding to a length of the nozzle surface.
The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing a method of maintaining an inkjet image forming apparatus, the apparatus having a print head and a print head wiper, the print head having a nozzle surface including nozzles to fire ink, the print head wiper having a rotatable first gear, a second gear engaged with the first gear, a cleaning roller fixed to the second gear, and a link arm to connect the first gear and the second gear, the method including rotating the first gear to revolve the second gear and the cleaning roller around the first gear until the cleaning roller contacts the nozzle surface, further rotating the first gear to rotate the second gear and the cleaning roller around an axis of the second gear to wipe the nozzle surface, spraying ink from the print head toward the cleaning roller, and absorbing the sprayed ink via the cleaning roller.
The method may further include heating the cleaning roller to evaporate the absorbed ink from the cleaning roller.
The method may further include cleaning the cleaning roller with a cleaning solution.
The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing a wiper unit to wipe an inkjet print head, the wiper unit including a cleaning unit to clean a nozzle surface of the print head, a rotatable cleaning gear connected to the cleaning unit to rotate the cleaning unit around an axis of the cleaning gear to clean the nozzle surface when the cleaning unit contacts the nozzle surface, a positioning gear to rotate the cleaning gear and the cleaning unit around an axis of the positioning gear to move the cleaning unit towards and away from the nozzle surface, and a driving unit to rotate the positioning gear.
The driving unit may include a worm guide to rotate the positioning gear and a motor to rotate to the worm guide. The wiper unit may further include a linker arm to connect the rotatable cleaning gear and the positioning gear, a first washer located between the linker arm and the cleaning gear to maintain a frictional force between the linker arm and the cleaning gear, and a second washer located between the linker arm and the positioning gear to maintain a frictional force between the linker arm and the positioning gear.
The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing an inkjet printer, including a print head including a plurality of nozzles and a nozzle surface, a platen to support a print medium as the print medium passes under the nozzle surface, a print head wiper to move adjacent to and clean the nozzle surface when the platen is away from a moving path of the print head wiper, and a platen moving mechanism to move the platen away from the moving path of the print head wiper.
The platen may include a pair of bosses on one side of the platen, and the platen moving mechanism may include a platen motor and a platen gear to move the platen closer to or further from the nozzle surface based on a rotational direction of the platen motor. The platen moving mechanism may further include a platen worm gear located on an end of the platen motor and being engageable with the platen gear to rotate the platen gear according to the rotational direction of the platen motor. The platen moving mechanism may further include a support having cam paths, the pair of bosses being insertable into the cam paths, an arm including a slot connecting the platen gear to the support and the bosses, the platen being moveable along the cam paths closer to or further from the nozzle surface based on a rotational direction of the platen motor. The print head wiper may include an outer layer to absorb ink cleaned from the nozzle surface, and a heater to transmit heat to the outer layer to evaporate ink absorbed in the outer layer. The print head wiper may further include an inner layer to transmit the heat from the heater to the outer layer. The print head wiper includes a cleaning roller to clean a nozzle surface of the print head, a rotatable cleaning gear connected to the cleaning roller to rotate the cleaning roller around an axis of the cleaning gear to clean the nozzle surface, a positioning gear to rotate the cleaning gear and the cleaning roller around an axis of the position gear to move the cleaning roller towards and away from the nozzle surface, and a driving unit to rotate the positioning gear.
The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing a cleaning roller to clean a nozzle surface of an inkjet print head, the cleaning roller including an outer layer to contact and to clean the nozzle surface, a support pipe to support the outer layer, and a heater inside of the support pipe to heat the support pipe. The support pipe may be a metallic support pipe. The heater may emit radiant heat to heat the support pipe. The outer layer may have an elliptical cross-section.
The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing a cleaning unit to clean a nozzle surface of an inkjet print head, the cleaning unit including a cleaning roller to rotate around an axis thereof to clean the nozzle surface when in contact therewith, a pivoting member to pivot the cleaning roller into contact with and away from the nozzle surface, and a driving member to drive the pivoting member. The pivoting member may include a cleaning gear connected to the cleaning roller to rotate the cleaning roller around the axis thereof to clean the nozzle surface, and a positioning gear to pivot the cleaning gear and the cleaning roller around an axis of the positioning gear to move the cleaning roller into contact with and away from the nozzle surface. The positioning gear may pivot the cleaning gear and the cleaning roller around an axis of the positioning gear to move the cleaning roller towards the nozzle surface until the cleaning roller contacts the nozzle surface, the cleaning roller may rotate around the axis thereof to clean the nozzle surface when the cleaning roller contacts the nozzle surface, and the positioning gear may pivot the cleaning gear and the cleaning roller around an axis of the positioning gear to move the cleaning roller away from the nozzle surface when a predetermined period of time has expired.
The foregoing and/or other aspects and utilities of the present general inventive concept may also be achieved by providing a method of cleaning a print head of an image forming apparatus, the print head having a nozzle surface, the method including moving a platen away from the nozzle surface, rotating a cleaning unit to contact the nozzle surface, and cleaning the nozzle surface. At least one of the moving, rotating, and cleaning operations may be performed when the image forming apparatus is in a standby mode. At least one of the moving, rotating, and cleaning operations may be performed when the image forming apparatus is in a continuous printing mode.
These and/or other aspects and advantages of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present general inventive concept by referring to the figures.
Referring to
The printing media conveyer may include an auto sheet feeder (ASF) roller 13 to pick up the printing medium (P) stacked in the media cassette 12 one-by-one, first feeder rollers 14 and second feeder rollers 15 that feed the picked-up printing medium (P) to the nozzle surface 22 of the print head 20, and ejection rollers 16 to eject the printing medium (P) to the media output tray 19 after the ink is fired onto the printing medium (P) to form the image on the printing medium (P). The ejection rollers 16 may include a driving roller 17 and a star wheel 18 facing the driving roller 17. The driving roller 17 drives the star wheel 18. If the printed printing medium (P) is pressed immediately after the ink is fired thereon, the image on the printing medium (P) can be damaged due to a spreading the the ink on the printing medium (P). Therefore, instead of using an idle roller, the star wheel 18 is used for the ejection rollers 16.
The print head 20, as illustrated in
Though not illustrated, the print head 20 includes chambers and passages to supply ink to the chambers. Each of the chambers communicates with the nozzle 26 and includes an ejection unit (e.g., a piezoelectric unit or a heater) to generate pressure to eject the ink. The chamber, the ejection unit, and the passage are well known to those of skill in the related art. Thus, descriptions thereof will be omitted.
The platen 30 is placed to face the nozzle surface 22 to keep the printing medium (P) spaced a predetermined distance from the nozzle surface 22 when the printing medium (P) passes under the nozzle surface 22. In various embodiments, the platen 30 may be at a distance of about 0.5 mm to about 2 mm apart from the nozzle surface 22 when the printing medium (P) passes under the nozzle surface 22. For example, the platen 30 may be a distance of about 0.5 mm to about 1 mm apart from the nozzle surface 22, or at a distance of about 1 mm to about 2 mm apart from the nozzle surface 22, when the printing medium (P) passes under the nozzle surface 22.
An embodiment of a printing operation using the inkjet image forming apparatus 10 will now be described.
The ASF roller 13 picks up the printing medium (P) stacked in the media cassette 12, and the first and second feeder rollers 14 and 15 feed the picked-up printing medium (P) to pass the printing medium (P) between the nozzle surface 22 of the print head 20 and the platen 30 at a constant speed. While the printing medium (P) advances at the constant speed, the nozzles 26 formed in the nozzle surface 22 selectively fire ink onto the printing medium (P) in a predetermined pattern to form the image. After the firing of the ink onto the print medium (P), the ejection rollers 16 stack the printed printing medium (P) in the media output tray 19.
The inkjet image forming apparatus 10 carries out maintenance at intervals during a standby mode or between print jobs during continuous printing. For the maintenance, the platen 30 is spaced apart from the nozzle surface 22 to expose the nozzle surface 22 and allow the print head wiper 50 to have access to the nozzle surface 22 without interference from the platen 30.
Referring to
Referring to
The link arm 60 has a first end connectable to a center of the first gear 51 and a second end connectable to a center of the second gear 53. A washer 64 may connect the center of the first gear 51 and the first end of the link arm 60 to maintain a frictional force between the first gear 51 and the first end of the link arm 60. Further, a washer 65 may connect the center of the second gear 53 and the second end of the link arm 60 to maintain a frictional force between the second gear 53 and the second end of the link arm 60. The washers 64 and 65 may be fitted within the centers of the first gear 51 and the second gear 53, respectively. Therefore, when the first gear 51 is rotated, the second gear 53 is revolved about the first gear 51 by the frictional forces between the link arm 60 and the first gear 51 and between the link arm 60 and the second gear 53. For example, if the first gear 51 is rotated in the counterclockwise direction, the second gear 53 may be revolved in an upward direction, and if the first gear 51 is rotated in the clockwise direction, the second gear 53 may be revolved in a downward direction. When the upward or downward revolution of the second gear 53 is restricted by an obstacle, the second gear 53 is not revolved around the first gear 51; however, the second gear 53 is still rotatable around its own axis by a driving force transmitted from the first gear 51.
The cleaning roller 55 may have a length corresponding to a length of the nozzle surface 22. The cleaning roller 55 may be fixed to the second gear 53 such that the cleaning roller 55 revolves and rotates with the second gear 53. When the cleaning roller 55 comes into contact with the nozzle surface 22, the cleaning roller 55 is rotated together with the second gear 53 about the axis of the second gear 53 to wipe the nozzle surface 22.
Referring to
The heater 57 may emit radiant heat to heat the support pipe 56, which in turn heats the outer layer 58. The heater 57 may be any heater suitable to emit radiant heat to the support pipe 56, such as a halogen lamp. However, the heater 57 is not limited to being a halogen lamp. The ink absorbed in the outer layer 58 after wiping or spraying is evaporated by the heat generated from the heater 57. Therefore, the print head wiper 50 does not require an additional tray to contain the wiped or sprayed ink.
Hereinafter, an embodiment of a method of maintaining the print head wiper 50 will be described with reference to
First, when the platen 30 (see
When the outer layer 58 covers the nozzle chips 24 as illustrated in
As a result, the second gear 53 and the cleaning roller 55 are revolved in the downward direction around the first gear 51 to the lower position, farther away from the nozzle surface, as illustrated in
However, the print head wiper 80 is different from the print head wiper 50 illustrated in
Specifically, when the first gear 81 is rotated in a clockwise direction (i.e., in the direction of the arrow in the first gear 81 in
In various embodiments, the method of maintaining the inkjet image forming apparatus using the print head wiper 80 illustrated in
According to various embodiments of the present general inventive concept, an inkjet image forming apparatus including a print head wiper can provide improved image quality by carrying out reliable maintenance of nozzles of the inkjet image forming apparatus.
According to various embodiments of the present general inventive concept, wiped and sprayed ink is absorbed by a cleaning roller, and then the absorbed ink is evaporated by heat, so that an inside of the image forming apparatus can be protected from contamination. Further, an additional tray is not required to collect the absorbed ink, thereby providing an image forming apparatus having a simple structure.
According to various embodiments of the present general inventive concept, a cleaning roller contaminated by ink can be cleaned by a cleaning roller presser part and/or by a cleaning solution, so that the consumable cleaning roller can be used much longer, i.e., so that the lifespan of the cleaning roller can be extended.
Although a few embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2005-59668 | Jul 2005 | KR | national |
