Patent Application
20130051900
This disclosure relates generally to printers having a drum and, more particularly, to the components for facilitating removal of media from an imaging receiving member after the media has passed through a transfix nip.
In known indirect, or offset, printing systems having a drum, the print process includes an imaging phase and a transfer phase. In ink printing systems, the imaging phase is the portion of the print process in which the ink is ejected from the nozzles in one or more printheads in an image pattern onto an image receiving member surface. The image receiving member typically has a very thin layer of release agent on its surface to facilitate transfer of the image from the image receiving member. The transfer phase is the portion of the print process in which the ink image is transferred from the image receiving member onto a recording medium. The image transfer typically occurs by bringing a transfer roller into contact with the image receiving member to form a nip. A recording medium arrives at the nip as the image receiving member rotates the ink image through the nip. The pressure in the nip helps transfer the image formed of malleable inks from the image receiving member to the recording medium.
In some indirect printers, a stripper blade is used to intervene between the leading edge of a media leaving the transfer nip and the image receiving member to facilitate separation of the media from the image receiving member after the image is transferred to the media. The stripper is pressed against the image receiving member by an actuator, such as a solenoid, to facilitate separation of the leading edge of the sheet from the image receiving member. After the sheet has passed through the nip, the actuator moves the stripper blade out of contact with the image receiving member to prevent excessive wear of the blade and image receiving member. Manual maintenance operations are periodically performed to the image receiving member and stripper blade. A second actuator is required to unlock the stripper to enable manual movement of the stripper from the image receiving member to allow sufficient clearance for the components that perform the manual maintenance operations. Using multiple actuators to operate the stripper system results in undesirable noise and excess moving parts. Similar components in a printer, such as media diverters, also require mechanisms for pivoting arms and unlocking of the components to facilitate maintenance, such as clearing paper jams. Consequently, improved mechanisms for operating printer components would be beneficial.
A pivoting assembly for a printer component has been developed that is simpler and requires fewer actuators. The pivoting assembly includes an elongated member having a first end and a second end, a protrusion extending from the elongated member, the protrusion extending transversely to a length of the elongated member from the first end of the elongated member to the second end of the elongated member, a pivot pin having a first end and a second end, the first end of the pivot pin being mounted through the elongated member at a position that enables the first end and the second end to move in a curved path about the pivot pin, a channel having a first horizontal planar surface and a second horizontal planar surface, the first planar surface and the second planar surface being parallel to one another and the second end of the pivot pin being positioned between the first horizontal planar surface and the second horizontal planar surface to constrain vertical movement of the pivot pin, a first cam positioned proximate the channel to enable the first cam to rotate past a portion of the pivot pin between the first end and the second end of the pivot pin and block a portion of the channel to stop horizontal movement of the pivot pin along the channel, a second cam positioned to enable the second cam to engage the protrusion extending from the elongated member, and an actuator having an output shaft that is operatively connected to the first cam and the second cam, the actuator rotates in a first rotational direction to rotate the second cam and the first cam until the first cam blocks the channel and prevents horizontal movement of the pivot pin in the channel and the second cam engages the protrusion extending from the elongated member and pivots the second end of the elongated member about the pivot pin in a first direction along the curved path to move the first end of the elongated member in the first direction along the curved path, and the actuator rotates in a second rotational direction that is opposite the first rotational direction to enable the elongated member to pivot along the curved path in a direction opposite the first direction, disengage the second cam from the protrusion extending from the elongated member, and move the first cam to a position that does not block the pivot pin in the channel.
A method of controlling pivoting movement of a printer component has been developed that facilitates movement of a printer component. The method includes rotating an actuator in a first rotational direction, rotating a first cam with the rotation of the actuator to position a portion of the first cam at a channel formed by two parallel surfaces to block horizontal movement of a pivot pin within the channel, the pivot pin being connected to the elongated member, which has a first end and a second end, rotating a second cam with the rotation of the actuator to move a surface on the second cam against a protrusion extending from the elongated member, the protrusion extending transversely to a length of the elongated member from the first end of the elongated member to the second end of the elongated member, and further rotation of the second cam with the actuator moves the protrusion in a curved path about the pivot pin to pivot the first end of the elongated member about the pivot pin.
The foregoing aspects and other features of an ink printer implementing a stripper blade assembly are explained in the following description, taken in connection with the accompanying drawings, wherein:
For a general understanding of the environment for the system and method disclosed herein as well as the details for the system and method, reference is made to the drawings. In the drawings, like reference numerals have been used throughout to designate like elements. As used herein, the word “printer” encompasses any apparatus that performs a print outputting function for any purpose, such as a digital copier, bookmaking machine, facsimile machine, a multi-function machine, or the like.
A stripper blade assembly 100 is shown in
The elongated member 144 includes a first end and a second end, the first end including a blade 152 that extends beyond the first end of the elongated member 144. A pin 156 is mounted on the second end of the elongated member 144 and the pin extends transversely to the length of the elongated member 144 into a space between the elongated member 144 and the second gear 128. The pin 156 is configured to engage an actuation surface 132 on the second cam. The elongated member 144 further includes a pivot pin 148 that is fixedly mounted to the elongated member 144 at a position near the center of the elongated member 144. The pivot pin 148 is substantially cylindrical and is constrained from movement in the vertical direction by two parallel horizontal surfaces 194, 198, which form the channel 190. The pivot pin 148 is configured to engage cam surfaces on the first cam 104, which guide the horizontal position of the pivot pin 148 when engaged. In the unlocked position depicted in
The first cam 104 includes a curved outer cam surface 112 and a curved inner cam surface 116, the inner cam surface 116 being concentric with the center of the first gear 108. The outer cam surface 112 is positioned outside the inner cam surface 116 and is arranged to enable the distance from the inner cam surface 116 to the outer cam surface 112 within channel 190 to decrease as the first cam 104 is rotated in direction 204. The outer cam surface 112 extends around approximately one quarter of the circumference of the first gear 108 in the illustrated embodiment, while the inner cam surface 116 is a circle. The inner 116 and outer 112 cam surfaces are configured to guide the pivot pin 148 as the first cam 104 rotates in direction 204 and to constrain the horizontal movement of the pivot pin 148 until the pivot pin 148 is locked in a defined position.
The second cam 124 includes an actuating surface 132 that is positioned near the outside of the second cam 124 and gear 128. The actuating surface 132 is configured to engage the pin 156 of the elongated member 144 to enable the pin 156 to rotate the elongated member 144 about the pivot pin 148.
The stripper blade assembly 100 is shown in an unlocked position in
Cam surface 112 includes a dwell that constrains the pivot pin 148 in the channel 190. In response to the stripper being rotated against the drum, both the second and the first cams rotate, while pivot pin is constrained within the channel 190 by the dwell portion of the cam surface 112. This dwell portion has a constant radius that is centered at the center of the first gear 108.
In response to a media sheet being affixed to the image receiving member 180, the motor 160 turns the output shaft 164 and drive shaft 168 further in direction 212. In response, the second gear 128 and second cam 124 rotate in direction 208. The actuation surface 132 of the second cam 124 forces the pin 156 of the elongated member 144 to pivot the elongated member 144 counter-clockwise about the pivot pin 148 until the blade 152 engages the surface 184 of the image receiving member 180. The blade 152 is designed to deform slightly to accommodate the shape of the surface 184 of the image receiving member 180, as shown in
In the position of
Another configuration of a stripper blade assembly 300 is shown in
The elongated member 344 includes a first end and a second end, the first end having a blade 352 extending beyond the first end of the elongated member 344. A pin 356 is mounted on the second end of the elongated member 344. The pin 356 extends transversely to the length of the elongated member 344 into a space between the elongated member 344 and the second gear 328. The pin 356 is configured to engage cam surfaces on the second cam 324 to guide the position of the pin 356. The elongated member 344 further includes a pivot pin 348 fixedly mounted near the center of the elongated member 344. The pivot pin 348 is substantially cylindrical and is constrained from movement in the vertical direction by two parallel horizontal surfaces 394, 398, which form the channel 390. The pivot pin 348 is configured to engage cam surfaces on the first cam 304 and these cam surfaces guide the horizontal position of the pivot pin 348 when engaged. In the unlocked position depicted in
The first cam 304 includes a curved outer cam surface 312 and a curved inner cam surface 316, which is concentric with the center of the first gear 108. The outer cam surface 312 is positioned outside the inner cam surface 316 and is arranged to enable the distance from the inner cam surface 316 to the outer cam surface 312 to decrease as the first cam 304 is rotated in direction 404. The outer cam surface 312 extends around only a portion of the first gear 108 in the illustrated embodiment. The inner 316 and outer 312 cam surfaces are configured to engage the pivot pin 348 as the first cam 304 rotates in direction 404 to constrain the horizontal movement of the pivot pin 348 until the pivot pin 348 is locked in a defined horizontal position by the cam surfaces 312, 316.
The second cam 324 includes a second inner cam surface 336 and a second outer cam surface 332. The second cam surfaces 332, 336 are configured to engage the pin 356 of the elongated member 344 and enable the second cam surfaces 332, 336 to guide the pin 356 in a defined curved path so the elongated member 344 is pivoted about the pivot pin 348.
The stripper blade assembly 300 is shown in an unlocked position in
As the pivot pin 348 moves into the locked position of
When the stripper blade assembly 300 moves to the locked position of
In response to a media sheet being printed on the image receiving member 380, the motor 360 turns the output shaft 364 and drive shaft 368 further in direction 412. The second gear 328 and second cam 324 then rotate in direction 408. The first gear 308 no longer moves with the second gear 328, as the teeth of the first gear 308 are disengaged from the teeth of the second gear 328. As the second cam 324 rotates, the cam surfaces 332, 336 force the pin 356 of the elongated member 344 to pivot the elongated member 344 counter-clockwise about the pivot pin 348 until the blade 352 engages the surface 384 of the image receiving member 380. In the current configuration, the blade 352 is designed to deform slightly to accommodate the shape of the surface 384 of the image receiving member 380, as shown in
In the position of
As shown in
When a maintenance operation is required, the motor 360 rotates the output shaft 264 and drive gear 368 further in direction 424, as shown in
The above described embodiments of a stripper blade assembly enable the stripper blade to be manipulated for media stripping operations and moved to enable maintenance operations with a single actuator. Additionally, the assembly operates with reduced noise. The mechanism can be adapted to operate a diverter in a media transport system. The mechanism would be the same as the mechanisms described above with the substitution of a diverter arm for the elongated member and blade of the stripper blade assembly. The mechanism is positioned near a junction of a first media path and a second media path. Pivoting of the elongated arm would disrupt the first media path and divert media on the first media path onto the second media path. Reversing the pivot of the elongated arm as explained above would enable media on the first media path to remain on the first media path. Other adaptations are also possible.
Control system 68 aids in operation and control of the various subsystems, components, and functions of the printer 10. The control system 68 is operatively connected to one or more image data sources, such as a scanner, to receive and manage image data from the sources. The control system 68 also generates control signals that are delivered to the components and subsystems of the printer. Some of the control signals, such as firing signals for the printhead, are based on image data, while other control signals regulate the operating speeds, power levels, timing, actuation, and other parameters, of the printer components to cause the printer 10 to operate in various states, modes, or levels of operation, referred to collectively herein as operating modes. These operating modes include, for example, a startup or warm up mode, shutdown mode, various print modes, maintenance modes, and power saving modes.
The control system 68 is configured to ascertain relevant print job characteristics and attributes in a suitable manner, such as by parsing information in image data files or by monitoring the components and sensors of the printer. The print characteristics and attributes obtained by the control system include print media type, print size, fill or coverage level (i.e., percent of the print covered with ink), and whether the print is a simplex (image on one side) or a duplex (image on both sides) print.
The control system 68 includes a controller 70 and electronic storage or memory 74. The controller 70 has a processor, such as a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) device, or a micro-controller. Among other tasks, the processor executes programmed instructions that are stored in the memory 74. The controller 70 executes these instructions to operate the components and subsystems of the printer. Any suitable type of memory or electronic storage may be used. For example, the memory 74 may be a non-volatile memory, such as read only memory (ROM), or a programmable non-volatile memory, such as EEPROM or flash memory.
The controller 70 is operatively connected to a user interface (UI) 78. User interface (UI) 78 comprises a suitable input/output device positioned on the printer 10 to enable operator interaction with the control system 68. For example, UI 78 may include a keypad and display (not shown). The controller 70 is operatively connected to the user interface 78 to receive signals indicative of selections and other information input to the user interface 78 by a user or operator of the device. Controller 70 is also operatively connected to the user interface 78 to display information to a user or operator including selectable options, machine status, consumable status, and the like. The controller 70 is operatively connected to a communication link 84, such as a computer communication network, for receiving image data files and user interaction data from remote locations.
The ink loader 12 of the printer 10 is configured to receive phase change ink in solid form, such as blocks of ink 14, which are commonly called ink sticks. The ink loader 12 includes feed channels 18 into which ink sticks 14 are inserted. Although a single feed channel 18 is visible in
The melted ink from the melting assembly 20 is directed gravitationally or by actuated systems, such as pumps, to a melt reservoir 24. A separate melt reservoir 24 may be provided for each ink color, shade, or composition used in the printer 10. Alternatively, a single reservoir housing may be compartmentalized to contain the differently colored inks. As depicted in
The image forming system 26 includes at least one printhead 28. One printhead 28 is shown in
The printer 10 includes a rotating drum 34 as the image receiving member 34, although in alternative embodiments the image receiving member 34 is a moving or rotating belt, band, roller or other similar type of structure. A transfix roller 40 is configured for movement into and out of engagement with the image receiving member. The control system 68 selectively operates an actuator (not shown) to implement this movement. The transfix roller 40 is loaded against the transfer surface 30 of the image receiving member 34 to form a nip 44 through which sheets of print media 52 pass. The sheets are fed through the nip 44 in timed registration with an ink image formed on the transfer surface 30 by the printhead 28. Pressure, and optionally heat, generated in the nip 44 facilitates the transfer of the ink drops from the surface 30 to the print media 52 in conjunction with release agent to substantially prevent the ink from adhering to the image receiving member 34.
The pressure and heat applied to the media sheet 52 may urge the media sheet 52 against the imaging surface 30 after the media sheet exits the transfix nip 44. The stripper blade assembly 36 engages the imaging surface 30 and separates the media sheet 52 from the imaging surface 30 in a controlled manner. The media supply and handling system 48 receives the media sheet 52 after the stripper blade assembly separates the media sheet 52 from the image receiving member 34. The media supply and handling system 48 can move the media sheet 52 to an output area or return the media sheet through a duplex print path to enable duplex printing to a second side of the media sheet 52.
The image receiving member 34 includes an actuator (not shown) that drives the image receiving member to rotate at various predetermined velocities in response to control signals received from the control system 68. The various velocities include an imaging velocity and a transfixing velocity. The control system 68 is configured to operate an actuator to rotate the image receiving member 34 at the imaging velocity during imaging operations, i.e., when the ink images are formed on the transfer surface, and to rotate at the transfixing velocity during transfixing operations, i.e., when the print media are fed through the nip 44 in timed registration with the ink images formed on the transfer surface 30. The imaging and transfixing velocities may be different for different print jobs depending upon the characteristics of the print job, such as print job type, media type, job size, and coverage level, as well as drum surface condition, applicator oil transfer efficiency, properties of the oil, metering blade geometry, and desired oil film thickness. In one embodiment, the imaging velocity and the transfixing velocity are each between approximately 1200 mm/s and 2000 mm/s although any suitable velocity or range of velocities may be used for one or both of the imaging and transfixing velocities.
Media conditioning devices may be positioned at various locations along the media path 50 to prepare the print media thermally to receive melted phase change ink. In the embodiment of
It will be appreciated that various of the above-disclosed and other features, and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art, which are also intended to be encompassed by the following claims.
