1. Field of the invention.
The present invention relates to an imaging apparatus, and, more particularly, to a printhead carrier positioning apparatus and method.
2. Description of the related art.
A typical ink jet printer forms an image on a print medium by ejecting ink from a plurality of ink jetting nozzles of an ink jet printhead to form a pattern of ink dots on the print medium. The ink jet printhead may be formed integral with a cartridge containing a supply of ink, thus forming a printhead cartridge. Such an ink jet printer typically includes a reciprocating printhead carrier that transports one or more printhead cartridges, that mount the ink jet printheads, across the print medium along a bi-directional scanning path defining a print zone of the printer. A sheet feeding mechanism is used to incrementally advance the print medium sheet in a sheet feed direction, also commonly referred to as a sub-scan direction or vertical direction, through the print zone between scans in the main scan direction.
When the ink supply contained in one of the printhead cartridges is depleted, then typically the printhead cartridge is replaced. In order to simplify printhead cartridge replacement, some printers include an opening that provides a user with sufficient space to change-out the printhead cartridge.
What is needed in the art is a printhead carrier positioning apparatus and method to aid in the positioning of the printhead carrier at a cartridge exchange opening for convenient printhead cartridge replacement.
The present invention provides a printhead carrier positioning apparatus and method to aid in the positioning of the printhead carrier at a cartridge exchange opening for convenient printhead cartridge replacement.
The invention, in one form thereof, relates to an imaging apparatus. The imaging apparatus includes a housing having a cartridge exchange opening, and a printhead carrier system contained in the housing. The printhead carrier system has a printhead carrier. A cover is pivotably attached to the housing. The cover has an engagement surface. When the cover is in a closed position the cartridge exchange opening is not exposed. A switch unit has a switch actuator and a switch. The switch actuator is configured for actuating the switch. The engagement surface of the cover is positioned to engage the switch actuator when the cover is in the closed position. The switch actuator is configured with a button that is accessible by a user to facilitate manual manipulation of the switch actuator by a force applied to the button by the user. The printhead carrier is positioned based on an output of the switch.
In another form thereof, the present invention relates to a method for positioning a printhead carrier for an imaging apparatus. The method includes activating a printhead carrier drive system of the imaging apparatus to position the printhead carrier at a cartridge exchange opening when a cover of the imaging apparatus is detected to not be in a closed position; activating the printhead carrier drive system to position the printhead carrier at a printhead home position if the cover is not positioned in the closed position within a predetermined amount of time after being opened; and activating the printhead carrier drive system to reposition the printhead carrier at the cartridge exchange opening if, after the predetermined amount of time, the cover is open and a button is pressed by a user.
An advantage of the present invention is that it provides for convenient printhead cartridge replacement, even if the printhead cartridge has returned to a home position after the cover has been opened.
Another advantage of the present invention is that it reduces the chance of printer damage due to manual positioning of the printhead carrier by a user.
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 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 apparatus 10 includes a housing 12, and a cover 14 mounted to housing 12. Also mounted to housing 12 is a user interface 16 having control buttons, such as for example, a duplex button 18, a line feed button 20 and a power ON button 22. Imaging apparatus 10 also includes a media source 24 and a media exit tray 26.
As shown in
Referring to
Media source 24 is configured and arranged to supply from a stack of print media a sheet of print media 46 to feed roller unit 36, which in turn further transports the sheet of print media 46 during a printing operation.
Printhead carrier system 34 includes a printhead carrier 48 and a printhead carrier drive system 49.
Printhead carrier 48 carries, for example, one, two, three or more printhead cartridges, such as a monochrome printhead cartridge 50a and/or a color printhead cartridge 50b, that is mounted thereto. Monochrome printhead cartridge 50a includes a monochrome ink reservoir 52a provided in fluid communication with a monochrome ink jet printhead 54a and formed as an integral unit. Color printhead cartridge 50b includes a color ink reservoir 52b provided in fluid communication with a color ink jet printhead 54b and formed as an integral unit. Alternatively, printhead cartridges 50a, 50b may only include ink reservoirs 52a, 52b, which in turn are coupled to respective remote ink jet printheads 54a, 54b via respective fluid conduits.
Printhead carrier 48 is guided by a pair of guide members 56. Either, or both, of guide members 56 may be, for example, a guide rod, or a guide tab formed integral with imaging apparatus frame 44. The axes 56a of guide members 56 define a bi-directional scanning path 58 of printhead carrier 48.
Printhead carrier 48 is connected to printhead carrier drive system 49, which includes a carrier transport belt 60 that is driven by a carrier motor 62 via a carrier pulley 64. In this manner, carrier motor 62 is drivably coupled to printhead carrier 48, although one skilled in the art will recognize that other drive arrangements could be substituted for the example given, such as for example, a worm gear drive. Carrier motor 62 can be, for example, a direct current motor or a stepper motor. Carrier motor 62 has a rotating motor shaft 66 that is attached to carrier pulley 64. Carrier motor 62 is coupled, e.g., electrically connected, to controller 40 via a communications link 68.
At a directive of controller 40, printhead carrier 48 is transported in a controlled manner along bi-directional scanning path 58, via the rotation of carrier pulley 64 imparted by carrier motor 62. During printing, controller 40 controls the movement of printhead carrier 48 so as to cause printhead carrier 48 to move in a controlled reciprocating manner, back and forth along guide members 56. In order to conduct printhead maintenance operations, controller 40 controls the movement of printhead carrier 48 to position printhead carrier in relation to maintenance station 42 and/or cartridge exchange opening 32.
Ink jet printheads 54a, 54b are electrically connected to controller 40 via a communications link 70. Controller 40 supplies electrical address and control signals to imaging apparatus 10, and in particular, to the ink jetting actuators of ink jet printheads 54a, 54b, to effect the selective ejection of ink from ink jet printheads 54a, 54b.
During a printing operation, the reciprocation of printhead carrier 48 transports ink jet printheads 54a, 54b across the sheet of print media 46 along bi-directional scanning path 58, i.e., a scanning direction, to define a print zone 72 of imaging apparatus 10. Bi-directional scanning path 58, also referred to as scanning direction 58, is parallel with axes 56a of guide members 56, and is also commonly known as the horizontal direction. During each scan of printhead carrier 48 when printing, the sheet of print media 46 is held stationary by feed roller unit 36. Feed roller unit 36 includes a feed roller 74 and a drive unit 76. The sheet of print media 46 is transported through print zone 72 by the rotation of feed roller 74 of feed roller unit 36. A rotation of feed roller 74 is effected by drive unit 76. Drive unit 76 is electrically connected to controller 40 via a communications link 78.
Maintenance station 42 is provided for performing printhead maintenance. operations on the ink jet nozzles of ink jet printheads 54a, 54b. Such operations may include, for example, a printhead spit maintenance operation, a printhead wiping operation and a printhead capping operation. The printhead capping operation occurs with printhead carrier 48 located in a home position 80, which is a far-left position along mid-frame 38 with respect to the components arranged as shown in
Maintenance station 42 includes, for example, a maintenance housing 82 and a movable maintenance sled 84. Maintenance housing 82 supports movable maintenance sled 84, which has mounted thereto respective printhead wipers and printhead caps. Maintenance sled 84 is configured for movement in the directions generally depicted by double-headed arrow 86 to predefined elevations, such as for example, a lowered printing elevation, an intermediate wiping elevation and a fully raised capping elevation. Maintenance sled 84 includes a carrier engagement member 88.
With the orientation of components as shown in
Referring to
Cartridge exchange button 90 is used for both automatic and manual positioning of printhead carrier 48 at cartridge exchange opening 32 in accordance with the present invention. In the embodiment shown, cartridge exchange button 90 is mechanically linked to switch actuator 92, which in turn is communicatively linked to switch 94. Cover 14 includes an engagement surface 96, such as, for example, a protruding tab, positioned to engage cartridge exchange button 90 when cover 14 is moved to closed position 28 (
Switch 94 may be, for example, an electrical micro-switch or an optical switch, the operation of each being well known in the art. Switch 94 is communicatively coupled to controller 40 via a communications link 98. Controller 40 monitors switch 94 for a change in switch status, i.e., a logic low-to-high transition or a logic high-to-low transition. For example, with cover 14 in closed position 28 depicted in
Those skilled in the art will recognize that whether controller 40 senses a low-to-high transition or a high-to-low transition upon the depressing of cartridge exchange button 90 will depend upon the type of switching mechanism that resides in switch 94, e.g., a normally closed switching mechanism or a normally open switching mechanism.
Referring now to
In summary, referring to
At step S100, printhead carrier drive system 49 of imaging apparatus 10 is activated, via controller 40, to position printhead carrier 48 at a cartridge exchange position 114 (see
At step S 102, printhead carrier drive system 49 is activated, via controller 40, to position printhead carrier 48 at printhead home position 80 if cover 14 is not returned to closed position 28 within a predetermined amount of time after being opened, i.e., cover 14 remains open for too long. This predetermined amount of time may be, for example, in a range of 5 minutes to 50 minutes, or longer if desired, and serves to return printheads 54a, 54b to maintenance station 42 for capping to prevent liquid ink present in or on the nozzles of printheads 54a, 54b from drying and clogging.
At step S104, if, after the predetermined amount of time, cover 14 was not returned to closed position 28, and a user applies force F to cartridge exchange button 90, then printhead carrier drive system 49 is activated, via controller 40, to reposition printhead carrier 48 at cartridge exchange opening 32. Accordingly, even if printhead carrier 48 is no longer readily accessible by the time the user is ready to replace one or more of printhead cartridges 54a, 54b after cover 14 was originally opened, by pushing cartridge exchange button 90, the user may manually reposition printhead carrier 48 at cartridge exchange opening 32 in a manner that is not damaging to printhead carrier system 34.
While this invention has been described as having a preferred design, the present invention can 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.