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.
Light 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.
In 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 d1100 so as to be less than d2104 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 d1116a, 116b to be less than corresponding distances d2118a, 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.
This is a Divisional of U.S. Ser. No. 11/519,330 titled IMAGING APPARATUS WITH MEDIA PICKUP SYSTEM EMPLOYING CURVED SURFACE FOR MEDIA SEPARATION filed on 12 Sep. 2006 by Zwettler et al, incorporated herein by reference.
Number | Date | Country | |
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Parent | 11519330 | Sep 2006 | US |
Child | 12577886 | US |