MEDIA SEPARATOR FOR A PRINTING SYSTEM

FIELD OF THE INVENTION

The present invention generally relates to media feeding in a printer, and more particularly to a media separator to facilitate feeding one sheet at a time into the printing mechanism prior to printing.

BACKGROUND OF THE INVENTION

In a printing system a stack of paper or other print media is typically loaded at a media input location, from which the media is moved, one sheet at a time into a printing region for printing, and then is discharged from the printer. In order to pick one sheet at a time from the media input location, generally a media separator is located between the media input location and the printing region. If the paper is loaded too far into the printing mechanism, such that the lead edge of more than one sheet of paper is past the media separator, multiple sheets can inadvertently be fed, leading to paper jams and possible damage in the printer. It is well-known to incorporate a media stopper to keep the lead edges of the stack of paper from advancing beyond the media separator, until it is desired to move a sheet into the printing region for printing, and then retract the media stopper to let the sheet pass. Printing systems include line printing systems, which print a line of pixels substantially at one time (using a page-width printhead for example), and a carriage printer, which prints a swath of pixels. The examples described here will be for a carriage printer, but there can also be applicability for a line printing system.

In a carriage printer, such as an inkjet carriage printer, a printhead is mounted in a carriage that is moved back and forth across the region of printing. To print an image on a sheet of paper or other print medium, the medium is advanced a given nominal distance along a media advance direction and then stopped. While the medium is stopped and supported on a platen, the printhead carriage is moved in a direction that is substantially perpendicular to the media advance direction as marks are controllably made by marking elements on the medium - for example by ejecting drops from an inkjet printhead. After the carriage has printed a swath of the image while traversing the print medium, the medium is advanced, the carriage direction of motion is reversed, and the image is formed swath by swath.

FIG. 1 shows a schematic side view of a prior art carriage printer having a so-called L-shaped paper path. A variety of rollers are used to advance the medium through the printer. In this example, a pick roller 350 moves the first piece or sheet 371 of a stack 370 of paper (also generically called recording medium herein) at media input support 320 from paper load entry direction 301 toward media retention plate 340. Media retention plate 340 is disposed along media advance direction 304 and is at an angle a with respect to media input support 320. Angle a is typically greater than 60 degrees, so that when seen from the side view of FIG. 1, media input support 320 and media retention plate 340 look approximately like a letter L. A media stopper element (not shown) protrudes from media retention plate 340 in order to prevent media from advancing past the media separator 450. When paper is being moved out of the media input support for printing (as in FIG. 1), the media stopper element is retracted into the media retention plate 340. The media separator 450 resists motion of the bottom pieces of media so that only the first piece 371 of media is advanced past the media separator 450. After the piece 371 of recording medium moves past the retracted media stopper element and the media separator 450, it is then moved by feed roller 312 and idler roller(s) 323 to advance through the print region 303, and from there to a discharge roller 324 and star wheel(s) 325. Carriage 200 moves a printhead die 251 along a carriage scan direction that is into the plane of FIG. 1 and ink drops 270 are controllably ejected to print an image as the carriage is moved. Supporting the piece 371 of recording medium at print region 303 is a platen 390. In order to facilitate the printing of borderless prints where the image is printed to the edges of the recording medium, platen 390 can have support ribs 394 in between which is disposed an absorbent medium 392 to catch ink drops that are oversprayed beyond the edges of the recording medium.

A media separator typically includes a high friction member to provide an initial resistance to the passage of sheets of media, although the first piece of media being pushed by the pick roller must be able to be advanced reliably past the media separator. Particularly in an L-shaped paper path, multiple sheets of paper have a tendency to inadvertently move past the media separator at the same time, due to gravity and the flexibility of the sheets. What is needed is a low-cost media separator that reliably prevents the feeding of multiple sheets at the same time.

SUMMARY OF THE INVENTION

A preferred embodiment of the present invention includes a media separator for a media feeding apparatus that is configured to individually feed sheets of media in an inkjet printer. The media separator comprises a frame including a first surface and a second surface that is coplanar with the first surface. An elastomeric element is mounted in the frame and includes a base that is substantially parallel to the first surface and the second surface, a plurality of fingers extending substantially perpendicular to the base, each finger including a first end that is anchored to the base, and a second end that is free, wherein, when unbent, the second ends of the fingers extend through the gap beyond the first surface and the second surface, and wherein the first ends of the fingers do not extend beyond the first surface and the second surface. The plurality of fingers include a first finger, a second finger and a third finger, wherein a separation si between the first end of the first finger and the first end of the second finger along a length of the elastomeric element is equal or substantially equal to the separation si between the first end of the second finger and the first end of the third finger along the length of the elastomeric element. A thickness tl of the first finger along the length of the elastomeric element at the first end is such that 0.5sl < tl < 2sl . A thickness t2 of the first finger along the length of the elastomeric element measured in the plane of the first surface is such that t2 > 0.6tl . A width wl of the first finger at the first end is such that tl < wl < 3tl . A width w _m of the first finger along the length of the elastomeric element measured at a midpoint between the first end and the second end of the finger is such that w _m > 0.8wl .

The plurality of fingers are preferably arrayed in a plurality of rows where a first row includes the first finger and a fourth finger that is separated from the first finger by a distance dl as measured at the base of the elastomeric element, a second row including the second finger and a fifth finger that is separated from the second finger by the distance dl as measured at the base of the elastomeric element, and a third row including the third finger and a sixth finger that is separated from the third finger by the distance dl as measured at the base of the elastomeric element, wherein 0.5sl < dl < 2sl . A height of a first finger is equal to h, as measured between the first end and the second end, and a thickness of the first finger is equal to t, as measured along the length of the elastomeric element, wherein t < h < 5t. When a finger is bent such that its second end is offset from the first end along the length of the elastomeric element, the second end is moved to a position such that it does not extend beyond the first surface and the second surface. Another preferred embodiment of the present invention includes an inkjet printing system comprising a carriage that is movable along a carriage scan direction, a media input support, a media retention plate disposed at an angle with respect to the media input support, and a media separator for a feeding media. It includes a frame with a first surface and a second surface that is separated from the first surface by a gap, wherein the first surface and the second surface are

substantially parallel to a surface of the media retention plate, an elastomeric element mounted in the frame, the elastomeric element including a base that is substantially parallel to the first surface and the second surface, and a first finger and a second finger extending substantially perpendicular to the base and separated from each other in a direction perpendicular to the carriage scan direction. The first and second fingers include a first end that is anchored to the base and a second end that is free, wherein, when unbent, the second ends of the fingers extend through the gap beyond the first surface and the second surface, and wherein the first ends of the fingers do not extend beyond the first surface and the second surface. A first finger includes a face wherein the carriage scan direction is substantially parallel to the face. A pick roller is configured to move sheets of media from the media input support along a media advance direction past the media separator.

Another preferred embodiment of the present invention includes a media separator that is fabricated from an elastomeric material. The separator includes a base recessed between a pair of substantially horizontal media support surfaces. The elastomeric base includes a plurality of fingers extending from the base, wherein a portion of the ends of the fingers protrude past the media support surfaces. Those ends interfere with a movement of a sheet of media across the media support surfaces, preferably preventing them from moving across the media support surfaces. The fingers are formed in two parallel rows, side -by-side in pairs, such that a gap separates the fingers in each side-by-side pair. The elasticity of the fingers permits them to bend under a force of a media sheet that is being advanced by a pick roller wherein such a bent finger does not protrude past the media support surface. This allows the media sheet to advance past the media separator.

These, and other, aspects and objects of the present invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the present invention and numerous specific details thereof, is given by way of illustration and not of limitation. For example, the summary descriptions above are not meant to describe individual separate embodiments whose elements are not interchangeable. In fact, many of the elements described as related to a particular embodiment can be used together with, and possibly interchanged with, elements of other described embodiments. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications. The figures below are intended to be drawn neither to any precise scale with respect to relative size, angular relationship, or relative position nor to any combinational relationship with respect to interchangeability, substitution, or representation of an actual implementation.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features, and advantages of the present invention will become more apparent when taken in conjunction with the following description and drawings wherein identical reference numerals have been used, where possible, to designate identical features that are common to the figures, and wherein:

FIG. 1 is a schematic side view of a prior art printer having an L- shaped paper path;

FIG. 2 schematically shows an inkjet printer system;

FIG. 3 is a perspective view of a printhead;

FIG. 4 is a perspective view of a carriage printer;

FIG. 5 is a perspective view of the carriage of the printer of FIG. 4;

FIG. 6 is a perspective view a printhead mounted onto the carriage of

FIG. 5;

FIG. 7 is a perspective view of an ink tank loaded into the printhead of

FIG. 6;

FIG. 8 a perspective view of the carriage, printhead and ink tanks, rotated with respect to FIGS. 5-7;

FIG. 9 is a side perspective view of a portion of an inkjet printing system with the pick arm assembly biased to pivot toward the media input support;

FIG. 10 is a side perspective view of a portion of the inkjet printing system of FIG. 9 with the pick arm assembly pivoted away from the media input support;

FIG. 11 is a close-up perspective view of a media stopper; FIG. 12 is a side perspective view from an opposite side relative to

FIG. 9;

FIG. 13 is a close-up side perspective view similar to FIG. 10 with the pick arm assembly held away from the media input support;

FIG. 14 is a close-up side perspective view with the pick arm assembly biased against the media input support and the pick clutch assembly rotating toward engagement with the gear train;

FIG. 15 is a close-up side perspective view with the pick arm assembly biased against the media input support and the pick clutch assembly fully engaged to cause the media stopper to retract;

FIG. 16 is a close-up side perspective view with the pick arm assembly biased against the media input support and the pick clutch assembly rotating out of engagement with the gear train, allowing the media stopper to protrude;

FIG. 17 is a perspective close-up view of a rotatable arm; FIG. 18 is a perspective close up view of the rotatable arm, the pivotable pick arm assembly and a link arm that links them;

FIG. 19 is a close-up side perspective view of a portion of the views of FIGS. 14 and 15;

FIG. 20 is a side perspective view where the pick roller is moved farther away from the media input support than the gap provided when the ramp feature is engaged;

FIG. 21 is a close-up side perspective view of rotatable arm, pick clutch assembly, link arm and pivotable pick arm assembly;

FIG. 22 is a side perspective view of a portion of an inkjet printing system including a maintenance station;

FIG. 23 is a close-up perspective view of the region of the media separator according to a preferred embodiment of the present invention;

FIG. 24 is a close-up perspective view of the media separator of FIG.

23;

FIG. 25 is a close-up perspective view of the frame of the media separator of FIG. 23;

FIG. 26 is a close-up perspective view of the elastomeric element of the media separator of FIG. 23;

FIG. 27A is a top view and FIG. 27B is a cross-sectional view of the elastomeric element of FIG. 23; and

FIG. 28 is a schematic perspective view of a simplified example of an elastomeric element according to a preferred embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 2, a schematic representation of an inkjet printer system 10 is shown, for its usefulness with the present invention and is fully described in U.S. Patent No. 7,350,902 which is incorporated by reference herein in its entirety. Inkjet printer system 10 includes an image data source 12, which provides data signals that are interpreted by a controller 14 as being commands to eject drops. Controller 14 includes an image processing unit 15 for rendering images for printing, and outputs signals to an electrical pulse source 16 of electrical energy pulses that are inputted to an inkjet printhead 100, which includes at least one inkjet printhead die 110.

In the example shown in FIG. 2, there are two nozzle arrays 120 and 130 that are each disposed along a nozzle array direction 254. Nozzles 121 in the first nozzle array 120 have a larger opening area than nozzles 131 in the second nozzle array 130. In this example, each of the two nozzle arrays has two staggered rows of nozzles, each row having a nozzle density of 600 per inch. The effective nozzle density then in each array is 1200 per inch (i.e. d = 1/1200 inch in FIG. 2). If pixels on the recording medium 20 were sequentially numbered along the paper advance direction, the nozzles from one row of an array would print the odd numbered pixels, while the nozzles from the other row of the array would print the even numbered pixels.

In fluid communication with each nozzle array is a corresponding ink delivery pathway. Ink delivery pathway 122 is in fluid communication with the first nozzle array 120, and ink delivery pathway 132 is in fluid communication with the second nozzle array 130. Portions of ink delivery pathways 122 and 132 are shown in FIG. 2 as openings through printhead die substrate 111. One or more inkjet printhead die 110 will be included in inkjet printhead 100, but for greater clarity only one inkjet printhead die 110 is shown in FIG. 2. The printhead die are arranged on a mounting support member as discussed below relative to FIG. 3. In FIG. 2, first fluid source 18 supplies ink to first nozzle array 120 via ink delivery pathway 122, and second fluid source 19 supplies ink to second nozzle array 130 via ink delivery pathway 132. Although distinct fluid sources 18 and 19 are shown, in some applications it may be beneficial to have a single fluid source supplying ink to both the first nozzle array 120 and the second nozzle array 130 via ink delivery pathways 122 and 132, respectively. Also, in some embodiments, fewer than two or more than two nozzle arrays can be included on inkjet printhead die 110. In some embodiments, all nozzles on inkjet printhead die 110 can be the same size, rather than having multiple sized nozzles on inkjet printhead die 110.

The drop forming mechanisms associated with the nozzles are not shown in FIG. 2. Drop forming mechanisms can be of a variety of types, some of which include a heating element to vaporize a portion of ink and thereby cause ejection of a droplet, or a piezoelectric transducer to constrict the volume of a fluid chamber and thereby cause ejection, or an actuator which is made to move (for example, by heating a bi-layer element) and thereby cause ejection. In any case, electrical pulses from electrical pulse source 16 are sent to the various drop ejectors according to the desired deposition pattern. In the example of FIG. 2, droplets 181 ejected from the first nozzle array 120 are larger than droplets 182 ejected from the second nozzle array 130, due to the larger nozzle opening area. Typically other aspects of the drop forming mechanisms (not shown) associated respectively with nozzle arrays 120 and 130 are also sized differently in order to optimize the drop ejection process for the different sized drops. During operation, droplets of ink are deposited on a recording medium 20 (also sometimes called paper, print medium or medium herein).

FIG. 3 shows a perspective view of a portion of a printhead 250, which is an example of an inkjet printhead 100. Printhead 250 includes two printhead die 251 (similar to inkjet printhead die 110 of FIG. 2) that are affixed to a common mounting support member 255. Each printhead die 251 contains two nozzle arrays 253, so that printhead 250 contains four nozzle arrays 253 altogether. The four nozzle arrays 253 in this example can each be connected to separate ink sources. Each of the four nozzle arrays 253 is disposed along nozzle array direction 254, and the length of each nozzle array along nozzle array direction 254 is typically on the order of 1 inch or less. Typical lengths of recording media are 6 inches for photographic prints (4 inches by 6 inches) or 11 inches for paper (8.5 by 11 inches). Thus, in order to print a full image, a number of swaths are successively printed while moving printhead 250 across the recording medium 20. Following the printing of a swath, the recording medium 20 is advanced along a media advance direction that is substantially parallel to nozzle array direction 254. Also shown in FIG. 3 is a flex circuit 257 to which the printhead die 251 are electrically interconnected, for example, by wire bonding or TAB bonding. The interconnections are covered by an encapsulant 256 to protect them. Flex circuit

257 bends around the side of printhead 250 and connects to connector board 258. When printhead 250 is mounted into the carriage 200 (see FIG. 5), connector board

258 is electrically connected to a connector 244 on the carriage 200, so that electrical signals can be transmitted to the printhead die 251.

FIG. 4 shows a portion of a desktop carriage printer. Some of the parts of the printer have been hidden in the view shown in FIG. 4 so that other parts can be more clearly seen. Printer chassis 300 includes a horizontal base 302. Carriage 200 is moved back and forth in carriage scan direction 305, between the right side 306 and the left side 307 of printer chassis 300, while drops are ejected from printhead die 251 (not shown in FIG. 4) on printhead 250 that is mounted on carriage 200. A carriage motor (not shown) moves carriage 200 along carriage guide rail 382.

Printhead 250 is mounted in carriage 200, and multi-chamber ink supply 262 and single-chamber ink supply 264 are mounted in the printhead 250. The mounting orientation of printhead 250 is rotated relative to the view in FIG. 3, so that the printhead die 251 are located at the bottom side of printhead 250, the droplets of ink being ejected downward in the view of FIG. 4. Multi-chamber ink supply 262, for example, contains three ink sources: e.g. cyan, magenta, and yellow ink; while single-chamber ink supply 264 contains black ink. Toward the right side 306 of the printer chassis 300, in the example of FIG. 4, is the maintenance station 330.

In the L-shaped paper path shown in FIGS. 1, 4 and 9, the recording medium would be loaded along paper load entry direction 301 nearly vertically at an angle a of 60 degrees or more relative to horizontal base 302 (or relative to media retention plate 340, which is substantially parallel to base 302 in the example of FIG. 4) against media input support 320 at the rear 309 of the printer chassis. Media input support 320 includes a first side 321 and a second side 322. Media stopper elements 342 extend upwardly at an angle from media retention plate 340 in FIGS. 4 and 9. Media separator 450 is mounted on media retention plate 340 between two media stopper elements 342. Several rollers are used to advance the recording medium through the printer. A pick roller 350 on pick arm assembly 352 is rotated in rotation direction 351 to move the first piece or sheet 371 of a stack 370 of paper or other recording medium in media input support 320 from paper load entry direction 301 to the media advance direction 304 past media retention plate 340 past media separator 450 and toward feed roller 312. During pick roller rotation, the media stopper elements 342 are retracted into media retention plate 340 as described below, and the first piece of media 371 is advanced past the media separator. The first piece of media 371 is then moved by feed roller 312 (as it is rotated in forward rotation direction 313) and idler roller(s) 323 to advance toward the print region 303 (disposed along carriage scan direction 305). Because the pick roller 350 contacts a top side of the piece 371 of recording medium and the feed roller 312 contacts the opposite side, the rotation direction 351 of pick roller 350 is opposite the forward rotation direction 313 of feed roller 312 in order to advance piece 371 of recording medium through the printer. Feed roller 312 is driven directly by a paper advance motor (not shown) that is connected by belt or gear engagement, for example at drive gear 314. After the image is printed at print region 303, the piece 371 of recording medium is further advanced to a discharge roller 324 and star wheel(s) 325.

FIG. 5 is a perspective view of carriage 200. Carriage 200 includes a holder 202 for an inkjet printhead 250 (see FIGS. 3, 6-8). Printhead die 251 are exposed through window 204 of carriage 200 when printhead 250 is mounted onto carriage 200 (FIG. 8). Carriage 200 includes one or more bushings 205 to glide along carriage guide rode 382 (FIG. 4) in carriage scan direction 305. Carriage 200 also includes a connector 244 to mate with connector board 258 of printhead 250 (FIG. 3).

FIG. 6 is a perspective view of printhead 250 mounted in carriage 200. Printhead 250 includes compartment 272 for multi-chamber ink supply 262 (FIGS. 3 and 8) and compartment 274 for single chamber ink supply 264. Ink ports 271 receive ink from the ink supplies 262 and 264 and provide the ink to printhead die 251 of printhead 250. FIG. 7 shows a perspective view of multi-chamber ink supply 262 loaded into compartment 272 of printhead 250.

FIG. 8 is a bottom perspective view of the underside of carriage 200 together with printhead 250 and ink supplies 262 and 264. Sloped feature 210 is sloped relative to carriage scan direction 305 and is in line along carriage scan direction 305 with a corresponding ramped feature 412 (described below with reference to FIGS. 9 and 13), such that when sloped feature 210 is engaged with the ramped feature 412, the pivotable pick arm assembly 352 (including pick roller 350) is pivoted in a direction away from media input support 320 (FIG. 4). FIG. 9 is a side perspective view (from right side 306 of FIG. 4) of a portion of an inkjet printing system with the pick arm assembly 352 biased to pivot toward the media input support 320. Pick arm assembly 352 including pick roller 350, pick roller support arm 355 and support legs 356, is biased toward media input support 320 by biasing spring 354 located near but beyond the first side 321 of media input support 320. Biasing spring 354 is attached to pivotable support leg 356. The biasing support leg 356 near first side 321 has a number of gears mounted on it for transmitting rotational motion to the pick roller 350. A second biasing spring 354 is located near but beyond the second side 322 of media input support 321 as shown in FIG. 12, so that pick roller 350 is disposed between the two biasing springs 354. The biasing support leg 356 near second side 322 does not have gears attached to it (see FIG. 12). Pick roller support arm 355 is substantially parallel to carriage scan direction 305 and extends beyond the first side 321 and the second side 322 of media input support 320 in order to provide attachment points for the two biasing springs 354 at support legs 356 without interfering with the passage of recording medium (not shown). In FIG. 9, carriage 200 is not at its home position near maintenance station 330, so the sloped feature 210 (see FIG. 8) is not engaged with the ramped feature 412 located near maintenance station 330. As a result, biasing springs 354 hold pivotable pick arm assembly 352 so that pick roller 350 is against media input support 320, or against a top piece 371 of media (not shown) at media input support 320. This is the desirable position of the pick roller 350 for moving recording medium from media input support 320. However, if the user attempts to load a few sheets of recording medium having low stiffness while the pick roller 350 is biased against the media input support 320, the recording medium may become wrinkled or damaged while trying to load it.

Typically a user will load paper between printing jobs when the carriage 200 is at its home position at the maintenance station 330. FIG. 10 is a side perspective view of a portion of the inkjet printing system of FIG. 9 with the pick arm assembly 352 pivoted away from the media input support 320. The carriage 200 and the carriage guide rail 382 are hidden in the view of FIG. 10 so that the ramped feature 412 can be seen more clearly. The ramped feature 412, having been engaged by the sloped feature 210 on the carriage 200 as the carriage approaches the home position overcomes the biasing force of the biasing springs 354 and pivots the pivot arm assembly 352, including pick roller 350, away from media input support 320, as is described in further detail below. The amount of gap provided between the pick roller 350 and the media input support does not need to be large. It has been found that a gap of more than 2 mm (and up to 6 mm or more) is achievable in this manner. A 6 mm gap can accommodate approximately 60 sheets of media having a thickness of about 100 microns (i.e. about 0.004 inch). Even if the sheets individually have low stiffness, a stack of sheets has sufficient combined stiffness not to become wrinkled or damaged.

FIG. 11 is a close-up perspective view of a media stopper 341. Media stopper 341 includes a rotatable shaft 343 from which media stopper elements 342 extend. Near an end of rotatable shaft 343 is a lever 344 having a first contact surface 345. In this example, first contact surface 345 is a flat surface on the upper side of lever 344. A spring attachment feature 346 extends from lever 344. A spring 347 attaches to spring attachment feature 346 and biases the lever 344 upwardly along biasing direction 348, so that media stopper elements 342 normally extend upwardly through slots in media retention plate 340 as seen in FIGS. 4 and 9. As described below, in order to retract the media stopper elements 342 into media support plate 340, sufficient force must be applied to the first contact surface 345 of lever 344 in a direction opposite biasing direction 348 to overcome the biasing force of spring 347.

FIG. 12 is a side perspective view (from left side 307 of FIG. 4) of a portion of an inkjet printing system with the pick arm assembly 352 biased to pivot toward the media input support 320 as in FIG. 9. The second biasing spring 354 attached to support leg 356 located near second side 322 of media input support 320 can be seen in this view. In FIG. 12 media stopper elements 342 are hidden in order to more clearly show the slots 349 into which the media stopper elements retract during rotation of the pick roller 350, as described below. Media separator 450 is located between two slots 349. The media advance motor that powers drive gear 314 for feed roller 312 is hidden in FIG. 12, but the motor mount region 318 is indicated. The carriage is also hidden in this view.

FIG. 13 is a close-up side perspective view similar to FIG. 10 with the pick arm assembly 352 held away from the media input support 320. In FIG. 13, both the carriage and the maintenance station are hidden in order to more clearly show further details, including platen 390 (along print region 303), support ribs 394, pick clutch assembly 420, and gear train 430. In this close-up view it is also easier to see the gap between pick roller 350 and media input support 320 when the carriage is in the home position to pivot the pick arm assembly 352 away from media input support 320. Ramped feature 412 is a part of a rotatable arm 410 that is described in more detail below with reference to FIGS.17-19. (By a "rotatable" arm herein is meant an arm that can rotate or pivot in an arc about an axis, and does not imply that the arm can rotate in a full circle.) Rotatable arm 410 is linked to pick arm assembly 352 by link arm 440. Power to rotate pick roller 350 is contra llably provided by the media advance motor that drives feed roller 312 via drive gear 314 mounted on one end of the shaft of feed roller 312. Feed roller gear 311 is coaxially mounted on the opposite end of shaft. Idle gear 316 is always engaged with feed roller gear 311 and with first gear 422 of pick clutch assembly 420. In other words, first gear 422 of pick clutch assembly 420 is located proximate feed roller gear 311, but it is only indirectly engaged with feed roller gear 311 in this embodiment through idle gear 316. (In other embodiments, not shown, having no idle gear 316, the first gear 422 of pick clutch assembly can be directly engaged with feed roller gear 311.) Second gear 424 of pick clutch assembly 420 is engaged with first gear 422 and is selectively engageable with engaging gear 432 of gear train 430 (which includes the gears within the dashed line oval in FIG. 13). As described in more detail below, when the sloped feature 210 (FIG. 8) engages ramped feature 412, not only is pick arm assembly 352 pivoted about pivot point 436 on support leg 356, but also second gear 424 of pick clutch assembly 424 is held away from engaging gear 432 of gear train 430, so that no power is transferred to gear train 430. In particular, pick roller gear 434 is not rotated, so no rotational power is provided to pick roller 350. As described in more detail below, the application of force to first contact surface 345 of lever 344 (see FIG. 11) in order to overcome the biasing force of spring 347 is not provided unless the pick clutch assembly 424 is engaged with gear train 430 and pick roller 350 is being rotated. In other words, in the configuration of FIG. 13 with the carriage in the home position and holding the pick arm assembly 352 away from media input support 320, the biasing force of spring 347 will keep media stopper elements 342 extending upwardly from media retention plate 340.

FIGS. 14 and 15 are a sequence showing how the second gear 424 of pick clutch assembly 420 becomes engaged with engaging gear 432 of gear train 430 in order to provide rotational power to the pick roller and also provide the force on lever 344 of media stopper 341 in order to retract media stopper elements 342. In both FIGS. 14 and 15 the carriage (not shown) has been moved out of the home position so that ramped feature 412 is no longer engaged by the sloped feature on the underside of the carriage, so that pick arm assembly 352 is biased against the media input support. In FIG. 14 drive gear 314 is being driven in the reverse direction 317, causing both feed roller 312 and feed roller gear 311 also to be driven in the reverse direction (indicated by the arrow on the face of feed roller gear 311). The rotation of feed roller gear 311 in reverse direction cause the idler gear 316 and first gear 422 of pick clutch assembly 420 also to rotate, which causes pick clutch assembly 420 to rotate downward such that second gear 424 of pick clutch assembly 420 approaches engaging gear 432 of gear train 430. Pick clutch assembly includes an arm 428 having a second contact surface 429 on its bottom side, which is flat in the example shown in FIG. 14. As pick clutch assembly 420 rotates downward, second contact surface 429 of arm 428 approaches first contact surface 345 of lever 344. In FIG. 14, the second gear 424 of pick clutch assembly 420 is nearly engaged with engaging gear 432 but not quite, so no power is being transmitted to gear train 430. Even if second contact surface 429 of arm 428 touches first contact surface 345 of lever 344, insufficient torque would be generated to overcome the force of spring 347 in direction 348 before pick clutch assembly 420 is engaged with gear train 430, so the media stopper elements 342 continue to be biased to extend upward from media retention plate 340.

In FIG. 15, after continued reverse rotation of drive gear 314, feed roller 312 and feed roller gear 311, pick clutch assembly 420 has rotated into full engagement so that second gear 424 is engaged with engaging gear 432 of gear train 430. As a result, rotational power is transmitted through gear train 430 causing pick roller gear 434 and pick roller 350 to rotate in rotation direction 351 to move a piece of media (not shown) toward feed roller 312. As second gear 424 pushes against engaging gear 432 to transmit rotational power to gear train 430 and rotate pick roller 350, sufficient torque is now provided for second contact surface 429 of arm 428 to push first contact surface 345 of lever 344 with sufficient force to overcome the bias force of spring 347 that is directed along direction 348 (see FIG. 11), so that the media stopper elements (not shown in FIG. 15) are retracted into the slots 349 of media retention plate 340 and a piece of media is advanced past the media separator 450. Note that the direction of arrows 351 for rotation of the pick roller 350 and reverse direction 317 for the feed roller 312 are the same. However, because the pick roller 350 is in contact with the top side of the piece of media, and feed roller 312 is in contact with the bottom side of the piece of media, when the piece of media arrives at feed roller 312, the reversely rotating feed roller 312 tends to push the leading edge of the piece of media backwards. In this way any skew of the leading edge is substantially eliminated.

After the deskewing of the leading edge is completed, the media advance motor is driven in the forward direction to rotate drive gear 314, feed roller 312 and feed roller gear 311 in the forward direction 313. Forwardly rotating feed roller gear 311 causes idle gear 316 and first gear 422 of pick clutch assembly 420 to rotate such that second gear 424 of pick clutch assembly 420 is rotated out of engagement with engaging gear 432 of gear train 430, as shown in FIG. 16. As a result, no rotational power is transmitted through gear train 430, so no rotational power is provided to pick roller 350. In addition, second contact surface 429 of arm 428 of pick clutch assembly 420 no longer pushes on first contact surface 345 of lever 344, so that the biasing force of spring 347 in direction 348 (see FIG. 11) causes the media stopper elements 342 to again extend upwardly from media retention plate 340.

FIG. 17 is a perspective close-up view of rotatable arm 410 in isolation, as viewed approximately from the orientation of FIG. 12. When ramped feature 412 (located near first end 416) is engaged by sloped feature 210 on the underside of carriage 200 (see FIG. 8), rotatable arm 410 is rotated about hub 415 in rotation direction 413, causing linking hook member 414 to move substantially in direction 409. Linking hook member 414 attaches onto coupling pin 442 of link arm 440, as seen in FIG. 18, so that motion in direction 409 causes link arm 440 to pull on lug 358 on support leg 356, thereby causing support leg 356 of pivotable pick arm assembly 352 to pivot about pivot point 436. Coupling pin 442 is substantially parallel to carriage scan direction 305. Link arm 440 also includes a slot 444. When support leg 356 is being pivoted forward as in FIG. 18 (providing a gap between pick roller 350 and media input support 320 as in FIG. 11) the lug 358 is typically located at the end of the slot 444. A spring attachment member 418 located near second end 417 of rotatable arm 410 (opposite first end 416) is for attaching an extension spring 360 (see FIG. 18) to bias rotatable arm 410 against rotating in rotation direction 413. Thus, when the ramped feature 412 is engaged by sloped feature 210 on the underside of carriage, it needs to pull against both biasing springs 354 as well as extension spring 360.

FIG. 19 is a close-up side perspective view of a portion of the views of FIGS. 14 and 15 with some features hidden in order to show other features.

Extension spring 360 is shown as being detached from spring attachment member 418, but in a fully assembled printer it would be attached. Extension spring 360 is configured to pull rotatable arm 410 toward a predetermined position that is defined by bottom edge 419 being in contact with fixed stop 408. When sloped feature 210 of carriage 200 (see FIG. 8) is engaged with ramped feature 412 of rotatable arm 410, rotatable arm 410 is rotated away from this predetermined position.

As described above relative to FIG. 10, when carriage 200 is in the home position and ramped feature 412 is engaged, pivotable pick arm assembly 352 is pivoted forward to provide a gap of 2mm up to 6 mm or more between pick roller 350 and media input support 320. However, in many cases a user will want to load a stack of media that has a thickness of greater than the gap provided when the ramp feature 412 is engaged. Slot 444 of link arm 440 allows pivotable pick arm assembly 352 to pivot farther forward so that the pick roller 350 is moved away from media input support 320 by more than one centimeter without causing link arm 440 to push on rotatable arm 410. The side perspective view of FIG. 20 shows lug 358 of support leg 356 having moved along slot 444 in order to allow pick roller 350 to be moved farther away from media input support 320 than the gap provided when ramp feature 412 is engaged. FIGS. 18 and 20 also show that idle gear 316 is mounted at hub 415 of rotatable arm 410.

FIG. 21 is a close-up side perspective view of rotatable arm 410, pick clutch assembly 420, link arm 440 and pivotable pick arm assembly 352 in a configuration such that ramped feature 412 is engaged with sloped feature 210 of carriage 200 (see FIG. 8), and lug 358 is at the rear of slot 444. In this configuration a top edge 411, which is hook-shaped and located near second end 417 of rotatable arm 410 in this example, pulls on finger 426 of pick clutch assembly 420 so that second gear 424 is pulled out of engagement with engaging gear 432 of gear train 430. As a result, pick roller 350 is not rotated whether the feed roller 312 is rotated in the forward direction 313 or the reverse direction 317 (see FIGS. 14 and 16). Although arm 428 is mostly obscured from view in FIG. 21, finger 426 extends from arm 428. Because rotatable arm 410 pulls finger 426 when the sloped feature 210 of carriage 200 is engaged with ramped feature 412, second contact surface 429 of arm 428 is prevented from bearing against first contact surface 345 of lever 344, so that force is not applied to first contact surface 345 of lever 344. In other words, when the carriage is in the home position, the media stopper elements 342 will always be biased to extend upwardly from media retention plate 340, no matter whether or in which direction the feed roller 312 is rotated.

FIG. 22 is a perspective view of the right side 306 of printer chassis 300. Maintenance station 330 is similar to the maintenance station described in US Patent Application Publication 2009/0174748, which is incorporated by reference herein in its entirety. Activator arm 338 is analogous to the latching clutch arm of '748 and has a ramped surface similar to ramped feature 412. In particular, when carriage 200 moves all the way to its home position at maintenance station 330, sloped feature 210 on the underside of carriage 200 (see FIG. 8), not only engages ramped feature 412, but also activator arm 338. When activator arm 338 is engaged, power from the media advance motor is transmitted from feed roller gear 311 to a set of maintenance station gears (only one of which 339 is shown). As described relative to FIG. 21, when ramped feature 412 is engaged with sloped feature 210, no power is transmitted to pick roller 350, so there is no additional load on the media advance motor when it is powering the maintenance station 330. In addition, the media stopper elements 342 will always extend upwardly from media retention plate 340 when ramped feature 412 is engaged, independent of motor rotation. When the activator arm 338 is engaged and the media advance motor is rotated in a reverse direction to rotate the feed roller gear 311 in a reverse direction 317 (see FIG. 15), the wiper 332 is moved along direction 333 to wipe the printhead that is positioned over the maintenance station 330. Further reverse rotation of feed roller gear 311 causes cap 334 to move into a printhead capping position to prepare the printer for a period of nonprinting. Pump 336 can optionally be operated by further reverse rotation. When it is time to begin another print job, the media advance motor is rotated in a forward direction to rotate feed roller gear 311 in a forward direction 313 (see FIG. 16) and the cap 334 is moved out of the printhead capping position. Continued forward rotation of the media advance motor then causes wiper 332 to move in a direction that is opposite direction 333 in order to wipe the printhead. Pump 336 can optionally be operated by further forward rotation.

In FIG. 22 the housing of pick roller assembly 352 has been hidden in order to show pick roller drive shaft 353 and how it connects pick roller 350 with pick roller drive gear 432. Also, as seen in FIG. 21, both the ramped feature 412 of rotatable arm 410 and the activator arm 338 are located near maintenance station 330 so that they can both be engaged when the carriage 200 enters its home position at the maintenance station. Furthermore, in this preferred embodiment, activator arm 338 is between rotatable arm 410 and maintenance station 330. Also indicated in FIG. 22 is media separator 450 located between two media stopper elements 342, i.e. near slots 349.

FIG. 23 is a close-up perspective view of the region of the media separator 450 according to a preferred embodiment of the present invention. Media separator 450 is located between two media stopper elements 342. Media separator 450 has a frame 452 including a first surface 454 and a second surface 456 that is coplanar with the first surface 454. The first surface 454 and second surface 456 are separated by a gap 458 (see FIGS. 24 and 25). Mounting feature(s) 455 are used to attach frame 452 to media retention plate 340. Media retention plate 340 includes a raised surface 367 and a recessed surface 365. First surface 454 and second surface 456 are substantially coplanar with raised surface 367, and recessed surface 365 is recessed relative to the first surface 454 and the second surface 456. Media (not shown) is supported primarily by the raised surface 367 and first and second surfaces 454 and 456 of frame 452 of media separator 450 when the media stopper elements 342 are in the retracted position. These surfaces are typically formed of smooth, low- friction plastic. When a first piece of media (not shown) is being advanced, an edge of the piece of media bears against these low-friction surfaces.

Mounted in the frame 452 of media separator 450 is an elastomeric element 460 (see also FIGS. 24 and 26), which is preferably integrally formed, for example by molding. Elastomeric element 460 includes a base 462 that is substantially parallel to first surface 454 and second surface 456 and is recessed relative to those surfaces. Extending substantially perpendicular from base 462 are a plurality of fingers 465, each finger including a first end 466 that is anchored to the base 462, and a second end 467 that is free. Media separator 450 is configured such that when fingers 465 are unbent (as in FIGS. 23 and 24), the second ends 467 of fingers 460 extend through gap 458 and protrude beyond first surface 454 and second surface 456. The first ends 466 of fingers 460 do not extend beyond first surface 454 and second surface 456 because base 462 is recessed relative to those surfaces. Thus when media stopper elements 343 are retracted, second ends 467 of fingers 465 provide a barrier to advance of sheets of media. The media separator 450 is configured such that the mere weight of a sheet of media as it leans against the second end 467 of a finger 465 is insufficient to deflect the finger to a position such that the piece of media can advance past the finger 465. However, a piece of media that is being advanced by the pick roller 350 (see FIG. 1) is advanced with enough force to bend a finger 465 such that second end 467 is offset from first end 466 along the media advance direction 304 (i.e. along the length L of the elastomeric element 460 and along a direction that is substantially perpendicular to carriage scan direction 305) thereby moving second end 467 to a position (not shown) where it does not extend beyond first surface 454 and second surface 456, and the piece of media is allowed to pass. If the piece of media is located behind several fingers 465, each finger will be bent and passed in turn as the piece of media is advanced downstream by the pick roller.

Media separator 450 includes an upstream end 451 and a downstream end 453 opposite the upstream end 451, where the media is advanced in a direction 304 from the upstream end 451 toward the downstream end 453. Optionally the first surface 454 and second surface 456 are tapered downward such that they are recessed at downstream end 453 in order to provide less of a barrier as the piece of media is being advanced past media separator 450. With reference to FIGS. 26 and 27B, optionally at the downstream end 453 of the elastomeric element 460, one or more fingers 464 are provided with a lower height from raised platform 463 relative to base 462, where the raised platform 463 also tapers downward. Platform 463, side tab 478 and end tab 479 help to align and attach elastomeric element 460 to frame 452.

As shown in the example of FIG. 26 elastomeric element 460 of the media separator includes a first finger 471, a second finger 472 and a third finger 473, where the first finger 471 and the second finger 472 are separated by a distance si along the length L of elastomeric element 460, and likewise the second finger 472 and the third finger 473 are separated by the same (or substantially the same) distance si . The direction of separation between fingers 471, 472 and 473 is substantially parallel to media advance direction 304 and is substantially perpendicular to carriage scan direction 305. The thickness of fingers 471, 472 and 473 as measured at the base 462 (i.e. at the first ends 466 of the fingers) along the length L is tl . For ease of molding of the elastomeric element, and for providing sufficient separation for the bending of the fingers, it is preferable that 0.5sl < tl < 2sl . The thickness of the fingers tapers from the first end 466 toward the second end 467. The thickness t2 as measured in the plane of the first surface 454 (see FIG. 24) is preferably such that t2 > 0.6tl . The width wl of the fingers at first end 466 is preferably greater than the thickness tl but less than 3tl . In other words, tl < wl < 3tl .

In order to provide additional resistance to advancement of the media, fingers may be arrayed side by side in rows. For example in FIG. 26, a first row includes first finger 471 and fourth finger 474; a second row includes second finger 472 and fifth finger 475; and a third row includes third finger 473 and sixth finger 476. The distance between the side by side elements in a row (e.g. between first finger 471 and fourth finger 474) as measured at the base 462 of elastomeric element 460 is dl, and typically distance dl is constant or substantially constant among the rows. For ease of molding, it is preferable for dl to be within a factor of 2 of si . In other words 0.5sl < dl < 2sl . FIG. 27A shows a top view and FIG. 27B shows a cross-sectional view through A-A of FIG. 27A in order to more clearly indicate features, shapes and dimensions of elastomeric element 460.

A simplified example of a portion of the elastomeric element 460 is shown schematically in FIG. 28. Two fingers 465 are shown in their undeflected positions and a third finger 468 is shown being bent by the application of a force F applied at a lead edge 469. The plane 457 of the first surface 454 of frame 452 (see FIG. 24) is indicated by the horizontal dashed line. An unbent finger 465 has a height h relative to base 462 (i.e. from first end 466 to second end 467 of finger 465). An amount b of the height extends beyond the plane 457 of the first surface, and an amount h-b of the height is below the first surface of frame 452. A piece of media being advanced by the pick roller applies a force F at the lead edge 469 at the height of the plane 457 of the first surface and causes an amount of deflection a parallel to the media advance direction 304. The particular amount of deflection a shown in FIG. 28 causes second end 467 to move downward by an amount b to a position such that it does not extend beyond the plane 457 of first surface 454 and second surface 456 of frame 452. The piece of media is thus able to advance past the bent finger 468. After the piece of media is no longer applying force F to the bent finger 468, it returns to its unbent position, due to the elastic nature of the elastomeric material

The design of the media separator 450 can be guided with the aid of modeling. From cantilevered beam theory it is known that the amount of deflection a for a force F applied at the free end of a beam of length 1 and constant rectangular cross section with thickness t (parallel to the force F) and width w is given by

a = 4F1 ³ /Ewt ³ (1) where E is the elastic constant of the elastomeric element 460, and 1 ~ h - b since the load is applied at plane 457. Equation 1 is cited to give an

approximate indication of the role of various parameters.

Actual conditions are somewhat different than is assumed in equation 1. For example, in the actual example of an elastomeric element shown in FIGS. 26 and 27, the cross-section is not constant. Rather (also with reference to FIG. 28), the thickness of the finger 465 at its first end 466 near base 462 is tl, the thickness at the plane 457 of the first surface 454 of frame 452 is t2 and the thickness at the midpoint of the height of the finger is t _m . Typically the finger 465 is thickest near the base, and tapers toward the second end 467, so that tl > t _m > t2. Typically also the tip of the finger 465 at its second end 467 (above plane 457) is rounded. The rounded shape facilitates the piece of media passing the bent finger, and also reduces wear at the lead edge 469. In a particular example, the height h of finger 465 is 1.5 mm and the thickness tl at the base 462 is 1.0 mm. Face 461, which includes lead edge 469 and which is substantially parallel to carriage scan direction 305 (i.e. substantially perpendicular to media advance direction 304), does not extend perpendicularly from base 462 (as suggested in the simplified example of FIG. 28) but rather extends substantially perpendicularly at an angle of 102 degrees with respect to the base 462. The face opposite face 461 extends substantially perpendicularly at an angle of 94 degrees with respect to base 462. (Herein it is regarded that a face extending within 20 degrees of perpendicular to the base is substantially perpendicular to the base, and a finger 465 that extends substantially perpendicular to the base 462 is one where the face 461 containing the lead edge 469 and the face opposite face 461 are substantially perpendicular to the base 462.) Plane 457 is located a distance 1.2 mm above base 462. Thus, at plane 457, thickness t2 has tapered to approximately 0.7 mm. Also, at the midpoint of the height (i.e. at 0.75 mm above base 462) thickness t _m has tapered to approximately 0.8 mm. More generally, the thickness t _m at the midpoint of the height of finger 465 is greater than 70% thickness tl at the first end 466 near base 462. There can also be some tapering of the width w from the first end 466 to the second end 467 of finger 465. This can be beneficial in molding of the elastomeric element 460. Typically, the width w _m at the midpoint between the first end 466 and the second end 467 of finger 465 is greater than 80% thickness wl at the first end 466 near base 462.

Equation 1 indicates that the amount of deflection is proportional to the cube of the ratio of the length of the beam to its thickness for a beam of constant cross-section. Even for a non-constant cross-section, the deflection for a given amount of force F can be increased by making the distance from the base 462 to the point of application of force F at plane 457 larger than the thickness of finger 465. In designing the height, width, and thickness of finger 465 it is important to consider the elastic modulus of the elastomeric member 460, as well as the amount of deflection required to position the second end 467 so that it no longer extends past the plane of the first surface 454 of frame 452. It is also important to consider moldability considerations for good dimensional control on the elastomeric element 460. It is preferable for the thickness t _m at the midpoint of the height of finger 465 to be less than height h but greater than 20% of height h. In other words t _m < h < 5t _m , or more generally, for some thickness t of finger 465, t < h < 5t.

Requirements for the design of a media separator include reliability in preventing multiple sheets being fed at the same time (even for a variety of different media stiffnesses), low wear of the portion that the media is advanced against, negligible damage to the media, and low cost. Some prior art designs have a flat elastomeric element protruding through a frame. It has been found that the design of the present invention more reliably prevents inadvertent feeding of multiple sheets than a flat elastomeric element, particularly in an L-shaped paper path. Some prior art designs have an elastic element that is formed of a metal base plus a high friction coating, which can be susceptible to wear. In addition, the design of the present invention is more simply made at lower cost by integrally forming the elastomeric element, for example, by molding. Some prior art designs have an elastic element that includes metal arms plus a projection. Because the elastic modulus of a metal is relatively high, the arms are typically thin in order to allow displacement. If the projection is thin and relatively sharp, it can damage the media as it passes across the media separator. Some prior art designs include blocking elements that cause the media to bend as it passes the media separator, but this can damage some types of media. Some prior art designs include a sawtoothed elastomeric element where the tips of the teeth can deflect. The design of the present invention is less susceptible to wear of the ends of the fingers, because the finger bends throughout its height rather than primarily at the tips where the media strikes them. In summary, it is found that the design of the present invention is advantageous for reliability, wear, low damage, and low cost. PARTS LIST

Inkjet printer system

Image data source

Controller

Image processing unit

Electrical pulse source

First fluid source

Second fluid source

Recording medium

Inkjet printhead

Inkjet printhead die

Substrate

First nozzle array

Nozzle(s)

Ink delivery pathway (for first nozzle array)

Second nozzle array

Nozzle(s)

Ink delivery pathway (for second nozzle array)

Droplet(s) (ejected from first nozzle array)

Droplet(s) (ejected from second nozzle array)

Carriage

Holder

Window

Bushing

Sloped feature

Connector

Printhead

Printhead die

Nozzle array

Nozzle array direction

Mounting support member

Encapsulant

Flex circuit 258 Connector board

262 Multi-chamber ink supply

264 Single-chamber ink supply

270 Ink drops

271 Ink port

272 Compartment

274 Compartment

300 Printer chassis

301 Paper load entry direction

302 Base

303 Print region

304 Media advance direction

305 Carriage scan direction

306 Right side of printer chassis

307 Left side of printer chassis

309 Rear of printer chassis

311 Feed roller gear

312 Feed roller

313 Forward rotation direction (of feed roller)

314 Drive gear

316 Idle gear

317 Reverse rotation direction (of feed roller)

318 Motor mount region

320 Media input support

321 First side

322 Second side

323 Idler roller

324 Discharge roller

325 Star wheel(s)

330 Maintenance station

332 Wiper

333 Direction

334 Cap

336 Pump 338 Activator arm (for maintenance station)

339 Maintenance station gear

340 Media retention plate

341 Media stopper

342 Media stopper element

343 Rotatable shaft

344 Lever

345 First contact surface

346 Spring attachment feature

347 Spring

348 Lever biasing direction

349 Slot

350 Pick roller

351 Rotation direction

352 Pick arm assembly

353 Pick roller drive shaft

354 Biasing spring

355 Support arm

356 Support leg

358 Lug

360 Extension spring

365 Recessed surface

370 Stack of media

371 First piece of medium

382 Carriage guide rail

390 Platen

392 Absorbent material

394 Support ribs

408 Fixed stop

409 Direction

410 Rotatable arm

411 Top edge

412 Ramped feature

413 Rotation direction 414 Linking hook member

415 Hub

416 First end

417 Second end

418 Spring attachment member

419 Bottom edge

420 Pick clutch assembly

422 First gear (of pick clutch assembly)

424 Second gear (of pick clutch assembly)

426 Finger

428 Arm

429 Second contact surface

430 Gear train

432 Engaging gear (of gear train)

434 Pick roller drive gear

436 Pivot point

440 Link arm

442 Coupling pin

450 Media separator

451 Upstream end

452 Frame

453 Downstream end

454 First surface (of frame)

455 Mounting feature

456 Second surface (of frame)

457 Plane (of first surface of frame)

458 Gap

460 Elastomeric member

461 Face

462 Base (of elastomeric member)

463 Raised platform

464 Finger

465 Finger

466 First end (of finger) 467 Second end (of finger)

468 Bent finger

469 Lead edge

471 First finger

472 Second finger

473 Third finger

474 Fourth finger

475 Fifth finger

476 Sixth finger

478 Side tab

479 End tab