1. Field of the Invention
The present invention relates to performing printhead maintenance in an imaging apparatus, and more particularly, to a printhead wiper cleaning mechanism for an imaging apparatus.
2. Description of the Related Art
An imaging apparatus, such as an ink jet printer, includes a maintenance station that performs maintenance operations to preserve the life of the associated printhead. For example, an ink jet printer includes an ink jet printhead having a plurality of ink jetting nozzles formed in a nozzle plate. The ink jet printhead may be attached, for example, to a printhead cartridge having an integral ink reservoir.
Such a maintenance station for an ink jet printer includes a printhead wiper and a printhead capping mechanism. The printhead wiper is typically an elongated rubber device having a sharp wiping edge that is used for wiping residual ink from the nozzles of the ink jet printhead nozzle plate. The capping mechanism is used to cap the ink jet printhead for storage. The wiping and capping operations prevent the nozzles from becoming blocked with contaminants, such as dried ink and accumulated paper dust, thereby extending the life of the ink jet printhead.
Some ink jet printers accumulate a considerable amount of excess ink on the nozzle plate, particularly when printing at a high duty cycle. During printhead wiping maintenance, the printhead wiper is positioned to engage the excess ink on the nozzle plate, with most of the removed waste ink staying on the printhead wiper following the wiping operation. However, if the printhead wiper cannot hold all of the removed waste ink, then some of the waste ink may be deposited onto the side of the printhead. These occurrences can cause degradation in the wiping performance of the printhead wiper, since the waste ink remaining on the printhead wiper may be reapplied to the nozzle plate, or catapulted by the printhead wiper onto the sheet of print media when the printhead disengages from the printhead wiper. Also, some of the waste ink on the side of the printhead may fall onto the sheet of print media during a printjob.
In addition, some imaging apparatus include a printhead carrier having mounted thereto a semi-permanent printhead containing multiple nozzle plates. In such a configuration, there is not any excess space for the waste ink to be wiped onto a side surface, as may be the case for a printhead cartridge having a single printhead nozzle plate.
What is needed in the art is a printhead wiper cleaning mechanism for an imaging apparatus.
The present invention provides a printhead wiper cleaning mechanism for an imaging apparatus.
The invention, in one form thereof, relates to an imaging apparatus. The imaging apparatus includes a maintenance station mounting a printhead wiper having a waste ink collection surface. A printhead carrier carries a printhead and a printhead wiper cleaning mechanism for cleaning the printhead wiper. The printhead wiper cleaning mechanism includes a hook member for contacting the waste ink collection surface of the printhead wiper for removing residual waste ink from the waste ink accumulation surface as the printhead wiper cleaning mechanism moves relative to the printhead wiper.
The invention, in another form thereof, relates to a printhead cartridge, including a body, at least one printhead coupled to the body, and at least one printhead wiper cleaning blade coupled to the body.
In another form thereof, the invention relates to a printhead assembly, including a base, at least one printhead coupled to the base, and at least one printhead wiper cleaning blade coupled to the base.
An advantage of the present invention is that the printhead wiper may be cleaned, whereby reducing the chances of waste ink removed from a printhead from coming into contact with the sheet of print media.
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of exemplary embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
Referring now to the drawings, and particularly to
Imaging system 10 includes an imaging apparatus 14, which may be in the form of an ink jet printer, as shown. Thus, for example, imaging apparatus 14 may be a conventional ink jet printer, or may form the print engine for a multi-function apparatus, such as for example, a standalone unit that has faxing and copying capability, in addition to printing.
Host 12, which may be optional, may be communicatively coupled to imaging apparatus 14 via a communications link 16. As used herein, the term “communications link” is used to generally refer to structure that facilitates electronic communication between two components, and may operate using wired or wireless technology. Thus, communications link 16 may be, for example, a direct electrical connection, a wireless connection, or a network connection.
In embodiments including host 12, host 12 may be, for example, a personal computer including a display device, an input device (e.g., keyboard), a processor, input/output (I/O) interfaces, memory, such as RAM, ROM, NVRAM, and a mass data storage device, such as a hard drive, CD-ROM and/or DVD units. During operation, host 12 includes in its memory a software program including program instructions that function as a printer driver for imaging apparatus 14. The printer driver is in communication with imaging apparatus 14 via communications link 16. The printer driver, for example, includes a halftoning unit and a data formatter that places print data and print commands in a format that can be recognized by imaging apparatus 14. In a network environment, communications between host 12 and imaging apparatus 14 may be facilitated via a standard communication protocol, such as the Network Printer Alliance Protocol (NPAP).
Imaging apparatus 14, in the form of an ink jet printer, includes a printhead carrier system 18, a feed roller unit 20, a mid-frame 22, a media source 24, a controller 26 and a maintenance station 28. Printhead carrier system 18, feed roller unit 20, mid-frame 22, media source 24, controller 26 and maintenance station 28 may be mounted to an imaging apparatus frame 29.
Media source 24 is configured and arranged to supply from a stack of print media a sheet of print media 30 to feed roller unit 20, which in turn further transports the sheet of print media 30 during a printing operation.
Printhead carrier system 18 includes a printhead carrier 32 that carries, for example, one or more printhead cartridges, such as a monochrome printhead cartridge 34a and/or a color printhead cartridge 34b, which is removably attached thereto. Monochrome printhead cartridge 34a includes a monochrome ink reservoir 36a provided in fluid communication with a monochrome ink jet printhead 38a. Color printhead cartridge 34b includes a color ink reservoir 36b provided in fluid communication with a color ink jet printhead 38b. Alternatively, ink reservoirs 36a, 36b may be located off-carrier, and coupled to respective ink jet printheads 38a, 38b via respective fluid conduits. Also, alternatively, monochrome printhead cartridge 34a may be replaced with another color printhead cartridge, such as for example, a photo printhead cartridge.
Printhead carrier 32 is guided by a pair of guide members 40. Either, or both, of guide members 40 may be, for example, a guide rod, or a guide tab formed integral with imaging apparatus frame 29. The axes 40a of guide members 40 define a bi-directional scanning path 42 of printhead carrier 32. Printhead carrier 32 is connected to a carrier transport belt 44 that is driven by a carrier motor 46 via a carrier pulley 48. In this manner, carrier motor 46 is drivably coupled to printhead carrier 32, although one skilled in the art will recognize that other drive coupling arrangements could be substituted for the example given, such as for example, a worm gear drive. Carrier motor 46 can be, for example, a direct current motor or a stepper motor. Carrier motor 46 has a rotating motor shaft 50 that is attached to carrier pulley 48. Carrier motor 46 is coupled to controller 26 via a communications link 52. At a directive of controller 26, printhead carrier 32 is transported in a controlled manner along bi-directional scanning path 42, via the rotation of carrier pulley 48 imparted by carrier motor 46.
Ink jet printheads 38a, 38b are electrically connected to controller 26 via a communications link 54. Controller 26 supplies electrical address and control signals to imaging apparatus 14, and in particular, to the ink jetting actuators of ink jet printheads 38a, 38b, to effect the selective ejection of ink from ink jet printheads 38a, 38b.
During a printing operation, printhead carrier 32 transports ink jet printheads 38a, 38b across the sheet of print media 30 in a reciprocating manner along bi-directional scanning path 42, i.e., a scanning direction, to define a print zone 56 of imaging apparatus 14. Bi-directional scanning path 42, which is parallel with axes 40a of guide members 40, also may be referred to as main scan path 42 of printhead carrier 32. The sheet of print media 30 is transported in an incremental fashion through print zone 56 by the rotation of a feed roller 58 of feed roller unit 20. The rotation of feed roller 58 is effected by a drive unit 60. Drive unit 60 is electrically connected to controller 26 via a communications link 62.
Maintenance station 28 is provided for performing printhead maintenance operations on the ink jet nozzles of ink jet printheads 38a, 38b. Such operations may include, for example, a printhead spit maintenance operation, a printhead wiping operation and a printhead maintenance capping operation. Other services, such as for example, printhead priming and suction, may also be performed if desired by the inclusion of a vacuum device (not shown) of the type well known in the art. In order to conduct printhead maintenance operations, controller 26 controls the movement of printhead carrier 32 to position printhead carrier 32 in relation to maintenance station 28.
Maintenance station 28 includes a maintenance housing 64, a movable maintenance sled 66, and a sled latch mechanism 68. Maintenance housing 64 supports movable maintenance sled 66. Maintenance sled 66 is configured for movement in the directions generally depicted by double-headed arrow 70. The directions generally depicted by double-headed arrow 70 include both horizontal and vertical components. Mounted to maintenance sled 66 are a printhead wiper 72, a printhead wiper 74, a printhead cap 76 and a printhead cap 78. In this embodiment, printhead wiper 72 and printhead cap 76 will interact with printhead 38a, and printhead wiper 74 and printhead cap 78 will interact with printhead 38b.
Sled latch mechanism 68 is pivotably mounted to maintenance sled 66. Sled latch mechanism 68 cooperates with maintenance housing 64 and maintenance sled 66 to releasably latch maintenance sled 66 at a predefined elevation, such as for example, at an intermediate, or wiping, elevation.
Maintenance sled 66 includes a carrier engagement member 80. Maintenance sled 66 is biased by a biasing spring (not shown) in a direction toward printhead carrier 32. The spring force exerted by the biasing spring is sufficient to accelerate maintenance sled 66 and its associated components to the lowered (resting) position so that they are clear of printhead carrier 32 and ink jet printheads 38a, 38b as printhead carrier 32 returns to print zone 56.
With the orientation of components as shown in
Referring now also to
Printhead wiper cleaning mechanism 82 includes a hook member 94 and a base 96, from which hook member 94 extends. Hook member 94 is positioned for contacting waste ink collection surface 92 and wiping edge 90 of printhead wiper 72 for removing residual waste ink from waste ink collection surface 92 as printhead wiper cleaning mechanism 82 moves in a direction 97 relative to printhead wiper 72 along the bi-directional scanning path 42, i.e., the main scan path, prior to printhead wiper 72 contacting printhead 38a. As such, printhead wiper cleaning mechanism 82 is positioned on one side of printhead 38a in direction 97 of main scan path 42. The width of hook member 94 may be at least as wide as the width of wiper head 88 of printhead wiper 72 in a direction perpendicular to direction 97. Hook member 94 may be formed, for example, as a curved printhead wiper cleaning blade, and may be made from a rigid material, such as plastic. Hook member 94 may be attached to a body 98 of printhead cartridge 34a by a fastener 100, or may be attached by integral formation with body 98. Hook member 94 may include an arc-shaped surface 102 that faces outwardly from printhead 38a, so as to collect the residual waste ink removed from printhead wiper 72 as printhead 38a is moved by printhead carrier 32 in direction 97. Alternatively, arc-shaped surface 102 may be replaced by another geometric configuration, such as for example, a V-channel.
If bi-directional wiping is performed by printhead wiper 72, the optional printhead wiper cleaning mechanism 84 may be included on body 98 of printhead cartridge 34a. The structure, arrangement, and attachment of printhead wiper cleaning mechanism 84 is substantially the same as that described above with respect to printhead wiper cleaning mechanism 82, and thus for brevity will not be repeated here. With this dual structure, the printhead wiper cleaning mechanism 82 including its printhead wiper cleaning blade is spaced apart from printhead wiper cleaning mechanism 84 including its printhead wiper cleaning blade, with printhead 38a being located between printhead wiper cleaning mechanism 82 and printhead wiper cleaning mechanism 84. With this arrangement, the arc-shaped surfaces of each of printhead wiper cleaning mechanism 82 and printhead wiper cleaning mechanism 84 face away from printhead 38a.
In this embodiment, each of printheads 114a, 114b and printhead wiper cleaning mechanisms 82a, 82b is attached to base 112 of printhead assembly 110. Printhead carrier 108 is configured to receive one or more replaceable ink supplies for supplying ink to printheads 114a, 114b. Printhead wiper cleaning mechanism 82a is positioned to clean printhead wiper 72, prior to printhead wiper 72 wiping printhead 114a, as printhead carrier 108 travels in direction 97. Printhead wiper cleaning mechanism 82b is positioned to clean printhead wiper 74, prior to printhead wiper 74 wiping printhead 114b, as printhead carrier 108 travels in direction 97.
Optionally, printhead assembly 110 may include one or more of printhead wiper cleaning mechanisms 84 to facilitate bi-directional cleaning of the respective printhead wiper. The structure, arrangement, and attachment of printhead wiper cleaning mechanisms 82a, 82b and/or 84 is substantially the same as that described above with respect to
While the present invention has been described with respect to exemplary embodiments, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.