Imaging system

Information

  • Patent Grant
  • 6637328
  • Patent Number
    6,637,328
  • Date Filed
    Friday, June 16, 2000
    24 years ago
  • Date Issued
    Tuesday, October 28, 2003
    21 years ago
Abstract
An imaging system includes a guide which transports a recording medium and a roller which holds the recording medium in place to pull the recording medium through an imaging plane defined by a surface of the roller. A device forms an image onto the recording medium at the imaging plane. The roller is a vacuum roller that uses a vacuum produced at the imaging plane to hold the recording medium in place during transport and imaging.
Description




BACKGROUND OF THE INVENTION




This invention relates to an imaging system having a vacuum roller for transporting a recording medium.




Existing capstan imaging systems transport recording media by pulling the media through an imaging plane. Specifically, rollers in these imaging systems pinch the leading edge of the recording media and rotate to pull the media through the imaging plane. Because the leading edge of the recording media is pinched, images cannot be formed at, or near, the edge of the media.




SUMMARY OF THE INVENTION




In general, in one aspect, the invention is directed to an imaging system. The imaging system features a guide that transports a recording medium, and a roller that receives the recording medium from the guide and pulls the recording medium through an imaging plane defined by a surface of the roller. A device forms an image onto the recording medium at the imaging plane. This aspect of the invention may also include one or more of the following.




The roller is a vacuum roller that uses a vacuum produced at the imaging plane to pull the recording medium during imaging. A control system regulates a vacuum level of the vacuum roller so that the vacuum level is higher at a leading edge of the recording medium than at other portions of the recording medium. The imaging plane remains in a substantially constant location on the surface of the vacuum roller.




The guide defines a control point through which the recording medium is transported. The imaging plane is located after the control point in a direction that the recording medium is transported for imaging. The guide includes a set of rollers that pinch the recording medium to pull the recording medium. The roller rotates at a higher rotational velocity than rollers in the set of rollers. The roller rotates at substantially the same velocity as rollers in the set of rollers.




The device forms the image onto the recording medium starting substantially at a leading edge of the recording medium. The device is an optical imaging system that includes a laser. One or more recording medium editing devices are interposed between the guide and the roller. The one or more recording medium editing devices includes one or more of the following: a punching device for altering the recording medium, a vacuum bar for holding the recording medium during transport, and a cutting device for cutting the recording medium.




The imaging system may include a recording medium storage area. The guide receives the recording medium from the recording medium storage area and transports the recording medium from the recording medium storage area to the roller. The recording medium storage area includes a recording media cassette.











Other features and advantages of the invention will become apparent from the following description, including the claims and drawings.




BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a block diagram of an imaging system.





FIG. 2

is a flowchart showing a process for forming images using the imaging system.





FIG. 3

shows recording media used in the imaging system and images formed onto the recording media.





FIGS. 4 and 5

show perspective views of a vacuum roller used in the imaging system.





FIG. 6

shows a perspective view of the vacuum roller after it has been assembled.





FIG. 7

shows a cut-away side view of another vacuum roller that may be used in the imaging system.





FIG. 8

shows a cut-away front view of the vacuum roller of FIG.


7


.





FIG. 9

is a flowchart showing a process for controlling tension in recording media used in the imaging system of FIG.


1


.





FIG. 10

is a block diagram showing recording media being fed and rewound from a roll of media.





FIG. 11

shows a close-up view of air passageways created in the vacuum roller of

FIGS. 4 and 5

.





FIG. 12

shows a vacuum roller with transverse grooves.





FIG. 13

is a diagram of a vacuum belt for capturing and pulling recording media through an imaging plane.





FIGS. 14



a


,


14




b


and


14




c


show perforations that may be included on the belt of FIG.


13


.











DESCRIPTION





FIG. 1

shows an imaging system


10


. Imaging system


10


is a capstan imaging system. A capstan imaging system forms images onto recording media as the recording media is conveyed through the system. The components of imaging system


10


are described in detail below.




Imaging System




Imaging system


10


forms images onto recording media


12


. Recording media


12


may be a web-like material, such as polyester film, plate, or paper, or any other type of material including, but not limited to, rolls of sheet metal or individual metal plates. Flat sheets of recording media are fed into imaging system


10


manually. Recording media stored in rolls is fed from cassette


11


.




In this regard, a media spool


14


is included in cassette


11


for storing a roll


15


of recording media


12


. A motor


16


controls the supply of recording media from media spool


14


. Motor


16


operates to vary the torque on roll


15


as recording media


12


is fed from media spool


14


and to rewind recording media


12


back onto media spool


14


. A coupling, such as one or more pulleys


17


, controlled by motor


16


controls the rotation of media spool


14


.




Recording media


12


is fed from cassette


11


to a guide, which, in this embodiment, is comprised of rollers


19


. Rollers


19


transport recording media


12


from cassette


11


, through imaging system


10


, by clamping the recording media and pulling it through control point


20


to vacuum roller


21


. Rollers


19


include capstan roller


22


, which is driven by a motor (not shown), and pinch roller


24


, which rotates in response to rotation of capstan roller


22


.




Recording media


12


is fed from rollers


19


through several recording medium editing devices


25


. The operation of recording medium editing devices


25


is controlled by a computer, microprocessor or other controller (not shown). Guides (not shown) are used to guide the recording media through these editing devices.




Recording medium editing devices


25


include a vacuum bar


26


for holding the recording media during editing and a cutting device


27


for cutting the recording medium, as described below. Also included among recording medium editing devices


25


are optional punch


29


, leading edge punch


30


, and trailing edge punch


31


. These devices form (i.e., “punch”) holes in recording media


12


as recording media


12


is conveyed through imaging system


10


. Optional punch


29


forms holes, as directed, at predetermined locations of recording media


12


. Trailing edge punch


31


forms holes at the trailing edge of a sheet in recording media


12


and leading edge punch


30


forms holes at the leading edge of the sheet. Other devices may also be included for altering recording media


12


. For example, devices for forming slits or notches in recording media


12


may be included between vacuum roller


21


and rollers


19


.




Vacuum roller


21


captures (i.e., receives) recording media


12


and pulls recording media


12


through an imaging plane


32


, which is after control point


21


. Imaging plane


32


is defined by a surface


34


of vacuum roller


21


.




During transport, recording media


12


is held and pulled by a vacuum maintained by vacuum roller


21


. As described in more detail below, vacuum roller


21


includes a stationary cavity


35


at (i.e., adjacent to) imaging plane


32


. Holes (not shown in

FIG. 1

) are included in the surface of vacuum roller


21


so that when cavity


35


is evacuated, a vacuum is created through these surface holes. This vacuum acts as suction to pull recording media


12


during transport and imaging. Because cavity


35


is stationary, imaging plane


32


(the vacuum area) remains stationary even though vacuum roller


21


rotates.




A controller (not shown) regulates the vacuum level of vacuum roller


21


so that the vacuum level is higher at the leading edge of recording media


12


than it is at other portions of recording media


12


. The higher vacuum level at the leading edge of recording media


12


is needed to establish initial contact between vacuum roller


21


and recording media


12


. Once contact between vacuum roller


21


and recording media


12


has been established, the vacuum level can be lowered without vacuum roller


21


losing hold of recording media. The location of the leading edge of recording media


12


is known by the controller that regulates the vacuum level. That is, the controller keeps track of timing information, such as the length of the recording media, the rate at which the recording media is fed, and when sheets are cut from the recording media. The vacuum level is regulated based on this information.




Typically, the vacuum level is between zero and three PSI (pounds per square inch), which holds recording media between four mils and eight mils thick (one mil=1/1000 of an inch). However, the invention is not limited to using any particular vacuum level or to use with recording media having a particular thickness. The vacuum level can be adjusted as desired and/or the size, number and positioning of the surface holes on vacuum roller


21


can be varied to change the amount of suction applied to recording media


12


.




To keep recording media


12


taught between rollers


19


and vacuum roller


21


, the rotational velocity of vacuum roller


21


is set greater than the rotational velocity of capstan roller


22


(and, thus, of rollers


19


). Typically, the rotational velocity of vacuum roller


21


is 2% to 3% greater than that of rollers


19


; however, the invention is not limited to these numbers. Alternatively, the rotational velocity of vacuum roller


21


and capstan roller


22


may be substantially equal, which will also result in an amount of tension in recording media


12


.




As recording media


12


is transported through imaging plane


32


(i.e., the vacuum area), an imaging device


39


forms images onto the recording media at imaging plane


32


. Because recording media


12


is maintained flush with the surface of vacuum roller


21


during imaging, images can be formed over virtually the entire surface of recording media


12


, right up to its leading edge. By contrast, imaging systems that clamp recording media between pinch rollers and perform imaging behind such pinch rollers are unable to form images up to the leading edge of the recording media, since the leading edge of the recording media is clamped between the pinch rollers.




The imaging device in imaging system


10


includes a laser and optics (not shown) for scanning the laser over recording media


12


to expose recording media


12


. Recording media


12


is typically treated with photosensitive chemicals or the like so that exposure to light from the laser will result in the formation of images. The laser and its associated optics are controlled by a computer, microprocessor or other controller (not shown).




Once an image is formed onto recording media


12


, the direction of the recording media may be reversed for cutting and hole punching. That is, cassette


11


, rollers


19


, and vacuum roller


21


may be controlled to convey recording media


12


along the direction of arrow


40


, so that a sheet can be cut from recording media


12


. This process is described in more detail below.




Recording media


12


(either cut or uncut) is transported from vacuum roller


21


to media loop


41


. Media loop


41


is “non-tensioned” recording media, meaning that no, or substantially no, force is applied to the recording media


12


in media loop


41


. The absence of substantial force in media loop


41


reduces the chances that the recording media will be inadvertently pulled, thus causing imaging errors. A flap (not shown) or other device may be provided to “open” and “close” media loop


41


as needed.




Transport capstan rollers


42


clamp recording media


12


and transport recording media


12


to an image processing station


44


. Image processing station


44


contains chemicals, inks, and any other materials for developing the images formed by the laser onto recording media


12


. A flap (not shown) or other device may be provided to allow recording media


12


to enter image processing station


44


.





FIG. 2

is a flowchart showing how recording media


12


is conveyed through imaging system


10


. Recording media


12


is transported/conveyed (


201


) from recording media cassette


11


by rollers


19


. Recording media


12


is then subjected to any editing, such as hole punching or the like, performed by recording medium editing devices


25


. Vacuum roller


21


receives (


202


) recording media


12


. The vacuum level of vacuum roller


21


is adjusted (


203


), e.g., increased, so that vacuum roller


21


can establish contact with, and hold, the leading edge of recording media


12


. The vacuum level of vacuum roller


21


is then re-adjusted (


204


), e.g., decreased, once contact is established between vacuum roller


21


and recording media


12


. The laser is scanned across the surface of recording media


12


at imaging plane


32


to expose the recording media and form (


205


) images. An example of an image


45


formed on a sheet of recording media


12


is shown in FIG.


3


. Image


45


can be formed virtually right up to the leading edge


46


of recording media


12


.




Recording media


12


may then be cut (


207


) and the trailing edge thereof punched with holes. To do this, the direction of recording media


12


is reversed, as described above, and cutting device


27


cuts a sheet from recording media


12


. For example, recording media


12


may be cut along the trailing edge


47


of image


45


(

FIG. 3

) to form sheet


49


. At or about the same time, trailing edge punch


31


may form holes


38


near the trailing edge


47


of the cut recording media


12


(i.e., sheet


49


). Leading edge punch may, at or about the same time, form holes


43


corresponding to a leading edge


48


of a next sheet


50


to be cut from recording media


12


.




The direction of recording media


12


is then re-set to the “forward” direction (arrow


51


of FIG.


1


), meaning the “imaging” direction, and the cut sheet of recording media is conveyed by vacuum roller


21


to media loop


41


. Thereafter, the cut sheet of recording media is conveyed (


208


) by rollers


42


to image processing station


44


, where the image formed thereon by the laser (or whatever imaging device is used) is developed.




Vacuum Roller




As noted above, vacuum roller


21


captures recording media


12


and pulls recording media


12


through imaging plane


32


defined by a surface of vacuum roller


21


. Vacuum roller


21


contains surface holes and holds the recording media in place by suctioning air through these surface holes via a vacuum created within vacuum roller


21


.




First Embodiment





FIGS. 4 and 5

show close-up views of a vacuum roller


21




a


that may be used in imaging system


10


. Vacuum roller


21




a


contains caps


52


and


54


, axle


55


, and roller


56


.




Roller


56


can be formed of plastic, metal, or any other material. Roller


56


contains surface holes


57


and transverse holes


59


. Surface holes


57


are formed all, or part-way, through roller


56


and terminate at the surface


60


of roller


56


. Transverse holes


59


are formed through the sides


62


and


64


of roller


56


and intersect with the surface holes to form air passageways


65


within roller


56


(see FIG.


11


). As shown in

FIG. 11

, a single continuous air passageway


65


connects surface holes


57




a


and


57




b


and transverse hole


61




a


. The other surface and transverse holes of roller


56


also intersect to form similar air passageways.




Roller


56


is mounted on axle


55


, which in turn rotates within bearing surfaces


52




a


and


54




a


of caps


52


and


54


, respectively (in the directions of arrow


66


). Caps


52


and


54


are mated to the sides


62


and


64


, respectively, of roller


56


.

FIGS. 4 and 5

shows caps


52


and


54


before they are mated to roller


56


. The caps are mated by sliding the caps along axle


55


in the direction of arrows


67


and


69


.

FIG. 6

shows caps


52


and


54


mated to roller


56


. Caps


52


and


54


and roller


56


are mated so that a substantially air-tight seal is created between each cap and roller


56


. What is meant by “substantially air-tight”, in this context, is a seal that is air-tight or that has vacuum losses which do not significantly impair the functionality of vacuum roller


56


. Furthermore, caps


52


and


54


are mated to roller


56


so that caps


52


and


54


are held substantially stationary while roller


56


rotates. Caps


52


and


54


may be held stationary by mechanically attaching them to an immobile portion of image processing system


10


.




Caps


52


and


54


each include one or more cavities


70


on their inner surfaces


71


and


72


. Caps


52


and


54


are mated to the sides of roller


56


so that the cavities


70


in those caps are aligned to each other. Cavities


70


also align to transverse holes in roller


56


as roller


56


rotates. Because caps


52


and


54


are stationary relative to roller


56


, different transverse holes align with cavities


70


as roller


56


rotates.




Caps


52


and


54


include one or more vacuum connections


71




a


-


71




f


, which lead to the interior of cavities


70


. One or more vacuum devices


73




a


,


73




b


attach to the vacuum connections to evacuate the cavities


70


. Evacuating cavities


70


creates a vacuum in the transverse holes that are aligned to the cavities. This also creates a vacuum in the surface holes that intersect those transverse holes. As a result, suction is produced at those surface holes. Arrow


74


in

FIG. 11

shows the direction of air flow (i.e., vacuum/suction) produced by evacuating a cavity aligned to transverse hole


61




a


. The suction produced in this manner holds recording media


12


against vacuum roller


21




a


during transport and imaging.




Vacuum devices


73




a


,


73




b


may include internal (or external) valves or the like (not shown) for selectively controlling suction through vacuum connections


71




a


-


71




f


. For example, vacuum devices


73




a


,


73




b


may selectively activate such valves to create vacuums via vacuum connections


71




b


and


71




d


only (which align). This results in a decrease in the vacuum area/imaging plane produced by vacuum roller


21




a


, since the vacuum area will be smaller. Selective control over vacuum connections may be performed for the “single cap” vacuum roller described below.




As roller


56


rotates, different transverse holes align to cavities


70


; however, the area of roller


56


that contains the vacuum (imaging plane


32


of

FIG. 1

) remains stationary. This is because caps


52


and


54


, and thus cavities


70


that produce the vacuum, are stationary relative to roller


56


.




When recording media


12


comes into contact with imaging plane


32


of vacuum roller


21




a


, the suction produced by surface holes


57


pulls recording media


12


. When recording media


12


is conveyed beyond imaging plane


32


, the absence of vacuum beyond imaging plane


32


provides for relatively easy release of recording media


12


from vacuum roller


21




a


. That is, since there is relatively little or no vacuum beyond imaging plane


32


(there may be some vacuum resulting from the surface grooves described below), the recording media simply detaches from vacuum roller


21




a.






The surface holes of vacuum roller


21




a


are arranged in rows and are at substantially equal distances from one another. This provides a relatively uniform vacuum in imaging plane


32


. The size, number and locations of the surface holes and the transverse holes may vary, however, depending upon the desired vacuum level to be produced. Likewise, the holes need not be located at substantially equal distances from one another or in rows.




Roller


56


also includes surface grooves


75


. Surface grooves


75


are indentations in roller


56


that intersect with surface holes. Surface grooves


75


distribute the vacuum created by surface holes


57


over the surface of roller


56


. Distributing the vacuum over the surface of roller


56


results in a better hold on recording media


12


. Transverse surface grooves may also be included on roller


56


in addition to, or instead of, grooves


75


. Transverse surface grooves


78


are shown in

FIG. 12

for a vacuum roller


83


that is otherwise identical to vacuum roller


21




a.






Roller


56


may be fabricated as a single piece or it may be segmented, meaning that it may include plural interconnected segments. Among the advantages of using plural interconnected segments are ease of conventional manufacture and the ability to vary the size of roller


56


.




Although

FIGS. 4 and 5

show a vacuum roller having two caps, the invention is not limited as such. Rather, vacuum roller


21




a


may include a single cap. In this case, transverse holes


59


extend only out to the side of vacuum roller


21




a


that mates to the single cap. On the other side of vacuum roller


21




a


, the transverse holes terminate prior to reaching the exterior, in order to permit a vacuum to be formed using the single cap.




Second Embodiment





FIG. 7

shows a cut-away side view of another vacuum roller


21




b


that may be used in imaging system


10


; and

FIG. 8

shows a cut-away front view of vacuum roller


21




b


taken along line A—A of FIG.


7


. As shown in these figures, vacuum roller


21




b


includes stationary inner roller


80


, outer roller


81


, and a vacuum device


82


.




Stationary inner roller


80


and outer roller


81


may be made from any type of material, such as molded plastic or metal. Vacuum device


82


may be a commercially available vacuum device capable of suctioning air to produce a vacuum. The vacuum produced should be strong enough to hold a recording medium against vacuum roller


21




b


. Therefore, different vacuum devices may be used for different types of recording media, as is the case for all vacuum devices/sources described herein.




Stationary inner roller


80


includes cavity


84


, holes


85


, and axle


86


containing throughbore


87


. Axle


86


remains stationary during the rotation of outer roller


81


(described below). Axle


86


connects to vacuum device


82


via threading


90


(or any other type of connection). Vacuum device


82


suctions air out from throughbore


87


and holes


85


in order to evacuate cavity


84


. The air flow resulting from vacuum device


82


is shown by arrow


91


.




Outer roller


81


is concentric with stationary inner roller


80


and rotates about stationary inner roller


80


. Outer roller


81


contains surface holes


92


, which are similar to the surface holes on vacuum roller


21




a


(FIGS.


4


and


5


). Surface holes


92


are arranged around the circumference of outer roller


81


in rows. Surface holes


92


are at substantially equal distances from one another in order to provide a relatively uniform vacuum in imaging plane


32


. The size, number and locations of surface holes


92


may vary, however, depending upon the desired vacuum level to be produced, as was the case above. Likewise, the surface holes need not be located at substantially equal distances from one another or in rows.




Because inner roller


80


is substantially stationary, the location of cavity


84


and holes


85


does not change. On the other hand, the locations of surface holes


92


on outer roller


81


do change relative to inner roller


80


. However, the rotation of outer roller


81


ensures that some surface holes


92


will align with cavity


84


during rotation. As a result, the vacuum area (i.e., imaging plane


32




FIG. 1

) of vacuum roller


21




b


remains substantially stationary despite the rotation of outer roller


81


.




As was the case in

FIGS. 4 and 5

, outer roller


81


may include surface grooves (not shown). These surface grooves are indentations in outer roller


81


that intersect with surface holes


92


. The surface grooves distribute the vacuum from surface holes


92


over the surface of outer roller


81


. Distributing the vacuum over the surface of outer roller


81


produces a better, more even, hold of the recording media, as noted above. Transverse grooves like those of

FIG. 12

may also be included on vacuum roller


21




b.






Outer roller


81


may be fabricated as a single piece or it may be segmented, meaning that it may include plural interconnected segments. Among the advantages of using plural interconnected segments are ease of manufacture and the ability to vary the size of vacuum roller


21




b.






Although

FIG. 7

shows a single vacuum connection


90


, the invention is not limited as such. Rather vacuum roller


21




b


may include a vacuum connection on both sides


94


and


95


. In this case, throughbore


87


extends the entire length


96


of inner roller


80


. An additional vacuum may be added on side


94


to increase suction and/or to provide more uniform suction, if necessary. Likewise, several isolated cavities may be used in place of cavity


84


and those cavities may be selectively evacuated, as described above.




Inner roller


80


may also include a second stationary cavity


97


as shown by the dotted lines of FIG.


8


. The second cavity may include a connection to cavity


84


, such as a mechanical switch or the like (not shown), to release the vacuum in cavity


84


. This may be used, e.g., to release recording media from the imaging plane without turning off vacuum device


82


.




Third Embodiment




Instead of using a vacuum roller in imaging system


10


, a belt may be used in place of vacuum roller


21


to pull recording media to and through imaging plane


32


. Such a belt


110


is shown in FIG.


13


. Belt


110


may be located in the same location in imaging system


110


as vacuum roller


21


.




Belt


110


is driven around vacuum device


111


, a cavity located in chamber


120


, and rollers


114


and


115


. Vacuum device


111


creates a vacuum area in the cavity, via suction, located over an imaging plane


117


. Perforations


113


in belt


110


serve the same purpose as surface holes


57


in vacuum roller


21




a


. That is, the perforations move over the vacuum area and the vacuum from vacuum source


111


creates suction (in the direction of arrow


118


) at a stationary imaging plane. This suction acts to pull recording media


12


to and through the imaging plane. As shown, chamber


120


may include holes adjacent to the perforations for regulating the suction.




The perforations on belt


110


may be any shape. In

FIG. 14



a


the perforations are slits; in

FIG. 14



b


the perforations are holes; and in

FIG. 14



c


the perforations are in a checkerboard pattern. These perforation designs are merely representative; others may also be used.




Controlling Tension In Recording Media




Referring back to

FIG. 1

, in order to maintain a substantially constant recording media velocity and direction, tension should be maintained in recording media


12


between rollers


19


and recording media cassette


11


. This tension is controlled by controlling how recording media


12


is fed out of cassette


11


.




Recording media


12


is stored in a roll


15


that is held on media spool


14


of cassette


11


. The rate that recording media


12


is pulled out of cassette


11


is controlled by rollers


19


and corresponds to the diameter of the roll of recording media. As the diameter (“D”) of roll


15


decreases, the rotational velocity of the roll increases. The result is an increase in tension of the recording media between cassette


11


and rollers


19


.




To control this tension, imaging system


10


employs a process


99


(FIG.


9


). Specifically, imaging system


10


controls motor


16


to vary the amount of resistance (i.e., torque) to feeding recording media


12


out of cassette


11


based on the rotational velocity of roll


15


.




An encoder


100


(FIG.


1


), which can be a digital tachometer or the like, is connected to motor


16


to detect (


901


) the rotational velocity of roll


15


. Since the rotational velocity of the roll of recording media varies based on the diameter of the roll, there is no need to measure the diameter directly. However, direct measurements of the diameter may be used, if available.




The motor


16


applies (


902


) the torque to roll


15


. The torque is applied in any direction in order to maintain tension. For example, referring to

FIG. 10

, if recording media


12


is being fed from roll


15


in direction


101


, torque may be applied to roll


15


in direction


102


to decrease tension during feeding. Torque may be applied in the opposite direction as well to increase tension in the recording media.




A controller


103


(FIG.


1


), such as a motor servo, controls (


903


) the torque applied by the motor based on the rotational velocity of the roll detected by encoder


100


. Controller


103


controls the torque by varying the amount of current supplied to motor


16


. To increase the torque, controller


103


increases the amount of current supplied to motor


16


. This is done in response to a decrease in the rotational velocity of roll


15


, which corresponds to an increase in the diameter of roll


15


(this may occur, e.g., when a new roll of media is loaded). To decrease the torque, controller


103


decreases the amount of current supplied to motor


16


. This is done in response to an increase in the rotational velocity of roll


15


, which corresponds to a decrease in the diameter of roll


15


.




Motor


16


controls roll


15


through a coupling, such as one or more pulleys


17


connected to recording media cassette


11


. For example, referring to

FIG. 10

, as noted, if recording media


12


is being fed from roll


15


in the direction of arrow


101


, the applied torque will be in the direction of arrow


102


in order to decrease tension during feeding. Motor


16


can also be controlled to rewind recording media onto cassette


11


, as described above. The “rewind” direction is shown by arrow


104


of FIG.


10


.




Although a motor, encoder, and motor servo are described above to control torque, other devices may be used. For example, a digital controller may be used to control the motor based on the rotational velocity of the recording media. Other types of analog controls may be used as well. An electronic brake or an electronic clutch may be used in place of the motor to provide torque to the roll of recording media. Moreover, process


99


of

FIG. 9

is not limited to use with imaging system


10


. Rather, it may be used in any system, recording or otherwise, that requires tension in a medium being fed from a roll. Any one or more features of the apparatus and methods described herein may be combined to form a new embodiment not explicitly described.




Other embodiments not described herein are also within the scope of the following claims.



Claims
  • 1. An imaging system comprising:a guide which transports a recording medium, from a recording medium storage area, upon which an image is formed; a vacuum roller rotating in a first direction and having a vacuum that receives the recording medium from the guide and pulls the recording medium into initial contact with and through an imaging plane defined by a surface of the roller, and rotating in a second direction subsequent to completion of imaging to feed the recording medium to a cutting device, positioned between the storage area and said vacuum roller, that cuts the recording medium; and a device which forms an image onto the recording medium at the imaging plane.
  • 2. The imaging system of claim 1, wherein the cutting device is utilized subsequent to forming the image.
  • 3. The imaging system of claim 1, further comprising a control system for regulating a vacuum level of the vacuum roller so that the vacuum level is higher at a leading edge of the recording medium than at other portions of the recording medium.
  • 4. The imaging system of claim 1, wherein the imaging plane remains in a substantially constant location on the surface of the vacuum roller.
  • 5. The imaging system of claim 1, wherein the guide defines a control point through which the recording medium is transported, and the imaging plane is located after the control point in a direction that the recording medium is transported for imaging.
  • 6. The imaging system of claim 1, wherein the guide comprises a set of rollers that pinch the recording medium to pull the recording medium.
  • 7. The imaging system of claim 6, wherein the roller rotates at a higher rotational velocity than rollers in the set of rollers.
  • 8. The imaging system of claim 6, wherein the roller rotates at substantially the same velocity as rollers in the set of rollers.
  • 9. The imaging system of claim 1, wherein the device forms the image onto the recording medium starting substantially at a leading edge of the recording medium.
  • 10. The imaging system of claim 1, wherein the device comprises an optical imaging system that includes a laser.
  • 11. The imaging system of claim 1, further comprising one or more recording medium editing devices interposed between the guide and the roller.
  • 12. The imaging system of claim 11, wherein the one or more recording medium editing devices includes one or more of the following: a punching device for altering the recording medium, a vacuum bar for holding the recording medium during transport, and the cutting device.
  • 13. The imaging system of claim 1, wherein the guide receives the recording medium from the recording medium storage area and transports the recording medium from the recording medium storage area to the roller.
  • 14. The imaging system of claim 13, wherein the recording media storage area comprises a recording media cassette.
  • 15. The imaging system of claim 1, further comprising:a first roller positioned downstream of said vacuum roller; a second roller positioned downstream of said vacuum roller; said first and second rollers receiving a substantially non-tensioned portion of the recording medium.
  • 16. A method of transporting a recording medium in an imaging system, comprising:transporting the recording medium, from a recording medium storage area, using rollers; receiving the recording medium at a vacuum roller having a vacuum portion; activating the vacuum portion prior to the recording medium contacting the vacuum roller; rotating the vacuum roller in a first direction, thereby using the vacuum portion to pull the recording medium into initial contact therewith and through an imaging plane defined by the vacuum portion; forming an image onto the recording medium at the imaging plane; rotating the vacuum roller in a second direction using the to feed the recording medium to a cutter positioned between the vacuum roller and the recording medium storage area; and to cut the recording medium subsequent to said forming step.
  • 17. The method of claim 16, further comprising regulating a vacuum level of the vacuum roller so that the vacuum level is higher at a leading edge of the recording medium than at other portions of the recording medium.
  • 18. The method of claim 16, further comprising: punching the recording medium subsequent to completion of said forming step.
  • 19. The method of claim 16, wherein the imaging plane remains in a substantially constant location on the surface of the vacuum roller.
  • 20. The method of claim 16, wherein the vacuum roller transports the recording medium through the imaging plane at a higher speed than the rollers transport the recording medium from the recording media storage area.
  • 21. The method of claim 16, wherein the vacuum roller transports the recording medium through the imaging plane at substantially the same speed that the rollers transport the recording medium.
  • 22. The method of claim 16, wherein the image is formed onto the recording medium starting substantially at a leading edge of the recording medium.
  • 23. The method of claim 16, wherein the image is formed by scanning a laser beam over the recording medium.
  • 24. The method of claim 16, further comprising perforating the recording medium, subsequent to said forming step, as the recording medium is transported between the rollers and the vacuum roller.
  • 25. The method of claim 16, further comprising: relaxing a tension in the recording medium subsequent to said forming step.
  • 26. The method of claim 25, further comprising punching one or more holes in the recording medium after the direction of the recording medium has been reversed.
  • 27. The method of claim 16, further comprising receiving a non-tensioned portion of the recording medium between a first a first roller positioned downstream of said vacuum roller and a second roller positioned downstream of said vacuum roller.
US Referenced Citations (7)
Number Name Date Kind
4218973 Bouffard et al. Aug 1980 A
5243909 DeMoore Sep 1993 A
5268708 Harshbarger et al. Dec 1993 A
5636926 Yamaguchi Jun 1997 A
5865118 Fromson et al. Feb 1999 A
6043836 Kerr et al. Mar 2000 A
6336406 Wakabayashi et al. Jan 2002 B1