Imaging apparatus with media pickup system employing curved surface for media separation
A media pickup system suitable for use with an imaging apparatus including a pickup assembly including at least one pickup bar having a concave channel a curved surface, and an actuator configured to move the pickup bar between a first position and a second position, wherein the pickup assembly, when the pickup bar is in the second position, is configured to selectively engage and draw a portion of a first sheet of a stack of sheets of imaging media into the concave channel to bend the first sheet to create and air channel between and to separate the first sheet from a remaining portion of the stack of sheets of imaging media.
The present invention relates generally to an imaging apparatus, and more specifically to an imaging apparatus having a media supply system employing a channel having a curved surface for media separation.
BACKGROUND OF THE INVENTIONLight sensitive photothermographic film is used in many applications ranging from a standard photography apparatus to graphic arts to medical imaging systems. For example, laser imagers are widely used in the medical imaging field to produce visual representations on film of digital image data generated by magnetic resonance (MR), computer tomography (CT) or other types of scanners. Laser imagers typically include some type of film supply system, a film exposure system, a film processing system, and a transport system that moves film from the supply system along a transport path through the laser imager. Sheets of unexposed film are typically stacked within a standardized cartridge or magazine which is inserted into the laser imager. The supply system generally includes a mechanism for removing and providing individual sheets of unexposed film from the cartridge to the transport system for subsequent transport through the exposure and processing systems and delivery of a developed image to a dispensing area for access by a user.
When removing sheets of film from the cartridge, it is important that the supply system remove and provide only one sheet of film at a time from the cartridge to the transport system. Providing more than one sheet of film to the transport system can cause film jams along the transport path and result in poorly and/or improperly developed images requiring re-printing, resulting in lost productivity and potential damage to the imager. Unfortunately, due largely to vacuum-like effects between sheets, but also to a variety of factors such as, for example, static electricity and film coatings, sheets of photothermographic film tend to cling or stick together when placed in a stack, making removal of individual sheets of film from the stack difficult. In fact, when trying to lift/remove a top sheet of film from a stack, the attraction between the sheets of film is so strong that sometimes the entire stack clings to and is lifted with the top sheet. As a result, conventional film supply systems generally require a robust construction so as to be able to lift and support the weight of the entire film stack and complicated mechanisms to separate sheets.
One such film supply system includes a rotatable pickup head that employs suction cups to engage the top sheet of film of the stack. After the suction cups create a vacuum seal with the top sheet of film, the pickup head is rotated up and down between one or more positions to flex the film so as to separate the top sheet of film from the other sheets of the stack. An example of such a system is described by U.S. Patent Publication No. 2004/0169325 A1 to Nelson, filed on Feb. 28, 2003, which is assigned to the same assignee as the present invention, and is herein incorporated by reference. While this system is generally effective at removing the bulk of the lower sheets of the stack from the upper sheets of the stack, it is not always effective at separating the upper sheets of film from another, such as the one or more sheets immediately below the top sheet in the stack.
In light of the above, there is a need for an improved system for separating individual sheets of film from a stack of film of a film source of an imaging apparatus.
SUMMARY OF THE INVENTIONIn one embodiment, the present invention provides a media pickup system suitable for use with an imaging apparatus. The media pickup system includes a pickup assembly including at least one pickup bar having a concave channel with a curved surface and an actuator. The actuator is configured to move the pickup bar between a first position and a second position, wherein the pickup assembly, when the pickup bar is in the second position, is configured to selectively engage and draw a portion of a first sheet of a stack of sheets of imaging media into the concave channel to bend the first sheet to create an air channel between and separate the first sheet from a remaining portion of the stack of sheets of imaging media.
In one embodiment, the present invention provides an imaging apparatus including a media source including a stack of one or more sheets of imaging media and a pickup assembly. The pickup assembly includes a pickup bar moveable between a first position and a second position and having a concave channel with a curved surface, and a plurality of suction cups positioned in a spaced fashion in the concave channel and configured to contact a first sheet of imaging media of the stack when the pickup bar is in the second position. A vacuum system is configured to deliver a vacuum to the suction cups when the pickup bar is in the second position to cause the suction cups to engage the first sheet and to draw and deform the suction cups against the curved surface to bend the first sheet of imaging media to create an air channel between and separate the first sheet from a remaining portion of the stack.
By engaging and drawing the first sheet of media into the concave channel, the pickup assembly creates an air path between the first sheet and next sheet of media of the stack and breaks a vacuum bond between and separates the first sheet from a remainder of the stack. By separating the first sheet from the stack in this fashion, the media pickup system lifts only the first sheet (not the entire stack) and, thus, can be constructed of lighter weight materials, be more compact, and less expensive than conventional media pickup systems.
In one embodiment, media pickup system 40 includes a pickup assembly 50 and an actuator system 52. In one embodiment, as will be described in greater detail below, pickup assembly 50 includes a pickup bar having a concave channel 58 with a curved surface, in accordance with the present invention. In one embodiment, the concave channel 58 has a curvilinear surface (e.g. a “splined” profile). Actuator system 52 is configured to move the pickup bar between a first position and a second position. In one embodiment, when in the second position, pickup assembly 50 is positioned relative to the first sheet so that a length of the concave channel 58 is substantially parallel to a leading edge of the first sheet. In one embodiment, when the pickup bar is in the second position, pickup assembly 50 is configured to selectively engage and draw a portion of the first sheet of imaging media from the stack of sheet of media source 42 into and along the curved surface of the concave channel 58 to cause the first sheet to bend and separate from a remaining portion of sheets of the stack.
In one embodiment, after separating the first sheet from the stack of sheets, actuator system 52 is configured to deliver the separated first sheet of unexposed media to feeder assembly 38 by moving the pickup bar 56 of pickup assembly 50 to the first position. Feeder assembly 38, in-turn, delivers the sheet of unexposed media from pickup assembly 50 to a transport path 44 (indicated by the heavy dashed line). Media supply system 32 transports the unexposed film along transport path 44 to exposure system 34 which exposes a desired photographic image on the film based on image data (e.g. digital or analog) to form a latent image of the desired photographic image on the film. In one embodiment, exposure system 34 comprises a laser imager.
Media supply system 32 moves the exposed film along transport path 44 from exposure system 34 to processing system 36 which develops the exposed film. In one embodiment, processing system 36 comprises a thermal processor, such as a drum-type processor, which heats the exposed film to thermally develop the latent image. The developed film is cooled and moved by delivery and transport system 32 along transport path 44 to an output area 46, such as an output tray, for access by a user.
An example of an imaging apparatus similar to that described generally above by imaging apparatus 30 and suitable to be configured for use with media pickup system 40 is described by U.S. Pat. No. 6,007,971 to Star et al., which is herein incorporated by reference.
By engaging and drawing the first sheet of media into and along the curved surface of the concave channel 58, pickup assembly 50 creates an air path between the first sheet and next sheet of media of the stack (see
In one embodiment, as illustrated by the isometric view of portions of pickup assembly 50 in
As illustrated by
With reference to
It is noted that a level of vacuum pressure required to be provided by vacuum pump 80 to separate first sheet of imaging media 94 from stack 92 may vary depending on the size and type (e.g. coatings) of the imaging media and on the size of suction cups 66, 68, and 70, with larger suction cups generally requiring less vacuum pressure. However, the vacuum pressure must at least be at a level required to deform the suction cups 66, 68, and 70 and bend first sheet of imaging media 94, but less than a level that will cause suction cups 66, 68, and 70 to damage or create physical artifacts in first sheet of imaging media 94. In one embodiment, first sheet of imaging media 94 may be treated as a “beam” with vacuum pump 80 being required to provide at least enough vacuum pressure to deflect (i.e. bend) the beam (i.e. the film) into concave channel 58.
With reference to
Maintaining d1 100 so as to be less than d2 104 enables pickup assembly 50 and vacuum system 54 to more easily and more quickly bend first sheet of imaging media 94 and ensures that air channel 96 (see
However, as illustrated by
As illustrated, first and second suction cups 112a and 112b are positioned such that corresponding distances d1 to adjacent lateral edges 102a and 102b, illustrated as 116a and 116b, are less than corresponding distances d2 to leading edge 98, illustrated as 118a and 118b. Maintaining distances d1 116a, 116b to be less than corresponding distances d2 118a, 118b enables pickup bars 110a and 110b to more easily form corresponding air channels 120a and 120b (illustrated by dashed lines), which are in parallel with adjacent lateral edges 102a, 102b, when a vacuum is applied to first suctions cups 112a, 112b and second suction cups 114a, 114b. Similar to that described above with regard to air channel 96, the formation of longitudinal air channels 120a and 120b breaks bonds (a vacuum bond in particular) between first sheet of imaging media 94 and a remainder of the stack of imaging sheets 92 and enables pickup assembly 50 to more easily remove a sheet of imaging media from a stack than conventional sheet pickup assemblies.
In one embodiment, actuator system 52 is configured to move pickup bar 56 in a substantially linear fashion.
Linkage assembly 78 includes a drive linkage assembly 140 and a pair of idler linkage assemblies, illustrated as idler linkage assemblies 150a and 150b. Drive linkage assembly 140 includes a first drive link 142 and a second drive link 144. First drive link 142 is rotatably coupled via a pivot 146 to a structural element 147 of imaging apparatus 30. Second drive link 144 is rotatably coupled at one end via a pivot 148 to first drive link 142 and is rotatably coupled at the other end via a pivot 149 to pickup bar 56 (see
Idler linkage assemblies 150a and 150b respectively include first idler links 152a and 152b, and second idler links 154a and 154b. For illustrative purposes, only idler linkage assembly 150a is described in detail herein. First idler link 152a is rotatably coupled via a pivot 156 to structural element 147 (see
First drive link 142 is configured to rotate about pivot 146 in a plane defined by an x-axis 160 and a perpendicular z-axis 162, and second drive link 144 is configured to rotate about pivot 148 at first end and about pivot 149 at the a second end in substantially the same plane as first drive link 142. First idler link 152a is configured to rotate about pivot 156 in a plane defined by z-axis 162 and a y-axis 164, which is perpendicular to x- and z-axes 160 and 162, and second idler link 154a is configured to rotate about pivot 158 at a first end and about pivot 159 at a second end in substantially the same plane as first idler link 152a.
By respectively coupling pickup bar 56 to the second ends of second drive link 144 and second idler link 154a via pivots 149 and 159, movement of pivots 149 and 159 and pickup bar 56 is restricted to substantially linear movement along z-axis 162. As such, in one embodiment, rotation of a shaft 166 of motor 130 in a counter-clockwise motion causes first drive link 142, via gear train assembly 132, to rotate clockwise about pivot 146, which in-turn causes pickup bar 56, along with suction cups 66, 68, and 70, to move downward and toward imaging media stack 92 (with respect to
By employing linkage assembly 78, which restricts movement of pickup bar 56 in a substantially perpendicular fashion relative to imaging media stack 92, actuator system 52, according to embodiments of the present invention, requires less physical space (particularly in the dimension of z-axis 162) than conventional actuator systems that rotate a sheet pickup assembly along an arc relative to the stack of imaging media. Additionally, by moving pickup bar 56 in a perpendicular fashion relative to imaging media stack, suction cups 66, 68, and 70 are better able to make a seal connection with a top sheet of the stack relative to conventional actuator systems that rotate a sheet pickup assembly along an arc relative to the stack of imaging media.
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
Parts List
- 30 Imaging Apparatus
- 32 Media Supply System
- 34 Exposure System
- 36 Processing System
- 38 Feeder Assembly
- 40 Media Pickup System
- 42 Media Source
- 44 Transport Path
- 46 Output Area
- 50 Pickup Assembly
- 52 Actuator System
- 54 Vacuum System
- 56 Pickup Bar
- 58 Concave Channel
- 60 Mounting Slot
- 62 First Curved Surface
- 64 Second Curved Surface
- 66 Suction Cup
- 68 Suction Cup
- 70 Suction Cup
- 72 Edge of Suction Cup
- 74 Edge of Second Curved Surface
- 76 Actuator
- 78 Linkage Assembly
- 80 Vacuum Pump
- 82 Vacuum Line
- 84 Home Position
- 86 Drive Roller
- 88 Idler Roller
- 90 Stack of Sheets of Imaging Media
- 92 First Sheet of Imaging Media
- 96 Air Channel
- 98 Sheet of Imaging Media—Leading Edge
- 100 Distance “d1”
- 102 Sheet of Imaging Media—Lateral Edge
- 104 Distance “d2”
- 110a First Pickup Bar
- 110b Second Pickup Bar
- 112a First Suction Cup
- 112b First Suction Cup
- 114a Second Suction Cup
- 114b Second Suction Cup
- 116a Distance “d1”
- 116b Distance “d1”
- 118a Distance “d2”
- 118b Distance “d2”
- 120a Air Channel
- 120b Air Channel
- 130 Motor
- 132 Gear Train Assembly
- 140 Drive Linkage Assembly
- 142 First Drive Link
- 144 Second Drive Link
- 146 Pivot
- 147 Imaging Apparatus Structure
- 148 Pivot
- 149 Pivot
- 150a First Idler Linkage Assembly
- 150b Second Idler Linkage Assembly
- 152a First Idler Link
- 152b First Idler Link
- 154a Second Idler Link
- 154b Second Idler Link
- 156 Pivot
- 158 Pivot
- 159 Pivot
- 160 x-axis
- 162 z-axis
- 164 y-axis
- 166 Motor Shaft
Claims
1. A media pickup system suitable for use with an imaging apparatus, the media pickup system comprising:
- a pickup assembly including at least one pickup bar having a concave channel with a curved surface; and
- an actuator configured to move the pickup bar between a first position and a second position, wherein the pickup assembly, when the pickup bar is in the second position, is configured to selectively engage and draw a portion of a first sheet of a stack of sheets of imaging media into the concave channel to bend the first sheet to create an air channel between and separate the first sheet from a remaining portion of the stack of sheets of imaging media.
2. The media pickup system of claim 1, wherein the curved surface is a curvilinear surface.
3. The media pickup system of claim 1, wherein the pickup assembly includes a plurality of suction cups coupled to the pickup bar and positioned in a spaced fashion in and along a length of the concave channel and configured to contact a portion of a surface of the first sheet.
4. The media pickup system of claim 3, wherein the pickup assembly is configured to deliver a vacuum to the suction cups when the suction cups are in contact with the surface of the first sheet to form a vacuum seal between the suction cups and the first sheet, to draw the suction cups and the portion of the first sheet into the concave channel, and to deform the suction cups against the curved surface so as to bend and cause the first sheet to separate from a remaining portion of the stack.
5. The media pickup system of claim 4, wherein the suction cups are configured to extend beyond edges of the pickup bar to prevent contact between the first sheet of imaging media and the pickup bar.
6. The media pickup system of claim 4, wherein the pickup bar is positioned so that a distance between at least one of the suction cups and a lateral edge of the first sheet of imaging media is less than a distance between the suction cups and a leading edge of the first sheet of imaging media.
7. The media pickup system of claim 1, wherein a longitudinal dimension of the concave channel is positioned substantially parallel to a leading edge of the first sheet.
8. The media pickup system of claim 1, wherein the concave channel is configured to extend substantially across a width of the sheets of imaging media, wherein the width is defined as a distance between opposing lateral edges of the sheets of imaging media.
9. An imaging apparatus, comprising:
- a media source including a stack of one or more sheets of imaging media; and
- a pickup assembly including: a pickup bar moveable between a first position and a second position and having a concave channel with a curved surface; a plurality of suction cups positioned in a spaced fashion in and along the concave channel and configured to contact a first sheet of imaging media of the stack when the pickup bar is in the second position; and a vacuum system configured to deliver a vacuum to the suction cups when the pickup bar is in the second position to cause the suction cups to engage the first sheet and to draw and deform the suction cups against the curved surface to bend the first sheet to create an air channel between and separate the first sheet from a remaining portion of the stack.
10. The imaging apparatus of claim 9, wherein the curved surface is curvilinear in shape.
11. The imaging apparatus of claim 9, wherein a longitudinal dimension of the concave channel is positioned substantially parallel to a leading edge of the first sheet of imaging media when the pickup bar is in the second position.
12. The imaging apparatus of claim 11, wherein the pickup bar is positioned so that a distance between at least one of the suction cups and a lateral edge of the first sheet of imaging media is less than a distance between the suction cups and a leading edge of the first sheet of imaging media.
13. The imaging apparatus of claim 9, wherein the suctions cups of the plurality of suction cups are configured to extend beyond edges of the pickup bar to prevent contact between the first sheet of imaging media and the pickup bar.
14. The imaging apparatus of claim 9, wherein the level of vacuum pressure provided by the vacuum system is at a level high enough to deform the suction cups and to bend the first sheet of imaging media without damaging the first sheet of imaging media.
15. The imaging apparatus of claim 14, wherein a level of vacuum pressure provided by the vacuum system is based on characteristics of the sheets of imaging media.
16. The imaging apparatus of claim 9, further including an actuator system coupled to and configured to move the pickup bar between the first position and the second position.
17. The imaging apparatus of claim 9, further including:
- an exposure and processing system configured to form a desired image on a sheet of imaging media; and
- a feeder assembly configured to engage and deliver sheets of imaging media to the exposure and processing system, wherein the actuator system is configured to move to the pickup bar from the second position to the first position to provide the separated first sheet of imaging media from the pickup assembly to the feeder assembly.
18. The imaging apparatus of claim 17, wherein the vacuum system is configured to release the vacuum after engagement of the first sheet of imaging media by the feeder assembly.
19. A method of removing a sheet of imaging media from a stack of sheets of imaging media in an imaging device, the method comprising the steps of:
- positioning a pickup bar having a concave channel proximate to a first sheet of imaging media of the stack; and
- drawing a portion of the first sheet of imaging media into the concave channel to bend the first sheet to create an air channel between and separate from the first sheet from a remaining portion of the stack.
20. The method of claim 19, wherein positioning the pickup bar includes aligning a longitudinal dimension of the concave channel substantially parallel to a leading edge of the first sheet of imaging media.
21. An actuator system suitable for use with a media pick-up system of an imaging apparatus, the actuator system comprising:
- a drive linkage assembly including a drive point configured to move in a first plane defined by a first axis and a perpendicular second axis;
- at least one idler linkage assembly including an idler point configured to move in a second plane defined by the first axis and a third axis perpendicular to the first and second axes;
- a support element pivotally coupled to the drive point and pivotally coupled to the idler point such that together the drive point, idler point, and support element can move linearly along only the first axis; and
- an actuator coupled to and configured to apply a drive force to the drive linkage assembly to move the drive point along the first axis to move the support element linearly along the first axis.
22. The actuator system of claim 21, wherein the support element is coupled to a pickup mechanism of a media pickup system, wherein the pickup mechanism is configured to engage a major surface of a sheet of imaging media, and wherein the first axis is substantially perpendicular to the major surface.
23. The actuator system of claim 21, wherein the drive linkage assembly includes:
- a first drive link configured to rotate substantially in the first plane about first pivot; and
- a second drive link having a first end and coupled at a second end to the first drive link via a second pivot and configured to rotate in the first plane about the second pivot; wherein the drive point is proximate to the first end.
24. The actuator system of claim 23, wherein the idler linkage includes:
- a first idler link configured to rotate substantially in the second plane about a third pivot; and
- a second idler link having a first end and coupled at a second end to the first idler link via a fourth pivot and configured to rotate in the second plane about the fourth pivot, wherein the idler point is proximate to the first end.
25. The actuator system of claim 24, wherein the first and third pivots are coupled to a structural element of the imaging apparatus.
26. The actuator system of claim 24, including first and second idler linkage assemblies having corresponding idler points coupled to the support element.
27. The actuator system of claim 24, wherein the actuator is configured to provide a rotational force to the first drive link to rotate the first drive link about the first pivot.
28. The actuator system of claim 27, wherein the actuator comprises a motor having a rotating shaft, wherein the shaft comprises the first pivot to which the first drive link is coupled.
29. The actuator system of claim 27, wherein the actuator comprises a motor having a rotating shaft coupled to and configured to rotate the first drive link about the first pivot via a plurality of gears.
Type: Application
Filed: Sep 12, 2006
Publication Date: Mar 13, 2008
Inventors: Chris Zwettler (Stillwater, MN), Larry R. Boughten (Hugo, MN), Terrence H. Joyce (Lakeville, MN), Jay A. Esch (River Falls, WI)
Application Number: 11/519,330