Patent Application
20060043666
The present embodiments relate to photographic processing systems that utilize platens to transport print media.
Printing devices, such as inkjet printers and laser printers, use printing composition (e.g., ink or toner) to print text, graphics, or images onto a print medium in a print zone of the printing device. Inkjet printers may use print cartridges, also known as “pens”, which shoot drops of printing composition, referred to generally herein as “ink”, onto a print medium such as paper, film, transparencies or cloth. Each pen has a printhead that includes a plurality of nozzles. Each nozzle has an orifice through which the drops are fired. To print an image, the printhead is propelled back and forth across the print medium in the print zone by, for example, a carriage while shooting drops of ink in a desired pattern as the printhead moves. The particular ink ejection mechanism within the printhead may take on a variety of different forms known to those skilled in the art. In these types of devices as well as photographic processors, such as minilabs, kiosks etc., it is necessary to precisely transport and/or hold media between or at different stations of the device or processor.
A vacuum induced force is typically used to adhere a sheet of print media to a surface, for example, for holding a sheet of print media temporarily to a transport system or platen. Vacuum induced forces are also referred to as vacuum flows, vacuum, or suction, as best fits the context. Such vacuum hold-down systems are a relatively common, economical technology to implement commercially they can improve hard copy apparatus throughput without dramatic cost increase. For example, a rotating vacuum drum with holes through the surface is typically used, wherein a vacuum airflow through the chamber formed by the drum cylinder provides a suction force at the holes on the drum surface, as described in U.S. Pat. No. 4,237,466.
All vacuum holders with vacuum surfaces incorporate a series of channels and suction openings in the vacuum plate or drum, allowing for one or a few vacuum connections to provide suction over an area of the surface. In many early and some contemporary prior art systems, the internal vacuum plumbing is configured so that suction is applied to all suction openings simultaneously. Another approach for manufacturing vacuum holders is to use a “porous” surface instead of suction openings, where the pulling or vacuum is uniform through the entire surface. Regardless of the approach taken, a balance exists between the flow restriction of the surface and the vacuum source. A large suction force over a large area usually requires a low restricted porous material with a high capacity vacuum source. High capacity can mean high energy requirements that are wasteful and expensive. A need exists for a vacuum transport system that selectively has vacuum areas or controllable vacuum areas that can vary with different sizes of media.
Several problems are inherent in prior art configurations that result in a vacuum pumping requirement larger than the minimum needed to secure the print media. Consider the operation of a vacuum plate in which the print media is placed on the surface, covering some of the suction openings. Uncovered suction openings have a constant pumping requirement, and thus an excess capacity exists whose amount is determined by the minimum print media size. Covered suction openings have a large pumping requirement until a vacuum seal between the print media and surface is formed, at which time the pumping requirement diminishes, theoretically approaching zero for a perfect vacuum seal. The pumping requirement decreased from an initial value that must accommodate all of the covered suction openings to nearly zero as a vacuum seal is formed. Thus, prior art vacuum holders require vacuum pumps that are oversized relative to the minimum capacity needed to restrain the print media. A need exists for a system that utilizes smaller pumps.
Similar problems also occur in vacuum drum applications. The drum first makes contact with and picks up the leading edge of a flexible media. As the drum rotates, the media wraps about the drum and is held in place at the point of contact with the drum. In this application, the number of uncovered suction openings, and hence the pumping requirement, decreases as the rotation proceeds and suction openings are covered. A rotating drum can affect image quality. A need exists for a flat tray system.
Other problems with drums relate to the drum filling with debris so that the airflow is substantially reduced or eliminated, resulting in no securing force or insufficient securing force for holding the print medium, thereby rendering the printing device effectively inoperable.
Noise is another problem associated with the use of vacuum platens in printing devices. Noise is caused by airflow used to secure the print media to a belt or web transport as the airflow travels through the vacuum platen. The amount of noise varies depending on the particular configuration of the vacuum platen, but the noise can reach objectionable levels to some users of printing devices. In such cases, depending on the extent of user noise intolerance, printing device use will decrease or, even worse, cease altogether. A need exists to reduce the noise for printers that use vacuum transport devices.
A need exists for a system that alleviates these above-described problems, thereby helping minimize delay in the completion of printing tasks, helping maximize printing device throughput, helping prevent instances of waste of print media, and helping quiet annoying noise created during use of the printing device.
Other methods and devices directed at processing systems that utilize a vacuum platen device include U.S. Pat. No. 6,328,491; U.S. Pat. No. 6,371,430; U.S. Pat. No. 6,409,332; and U.S. Pat. No. 6,572,294. The listed prior art is hereby incorporated into the present application by reference.
The present embodiments described herein were designed to meet these needs.
A multi-chambered vacuum platen device includes a vacuum platen tray, a plate, a belt, and one or more vacuum ports. The vacuum platen tray includes numerous chambers. The tray transports varying sizes of photographic media to be processed. The plate is located on top of the multi-chambered tray. The plate includes slots that align with the chambers. The continuous belt is placed over the plate and around the bottom of the tray. The belt includes holes that align with the slots. One or more vacuum ports are located in the wall of the vacuum platen for providing selective suction.
In the detailed description of the preferred embodiments presented below, reference is made to the accompanying drawings, in which:
The present embodiments are detailed below with reference to the listed Figures.
Before explaining the present embodiments in detail, it is to be understood that the embodiments are not limited to the particular descriptions and that it can be practiced or carried out in various ways.
The present embodiments relate to printing and photographic processing systems that utilize a vacuum platen device to transport print media. The term “platen” herein refers to a flat holding surface or a curvilinear holding surface. For the purposes of the present application, the term “platen” is used generically for any shape paper hold-down surface, stationary or movable, as used in transport print media.
The present invention provides several advantages over the current art, namely, the platen is designed to require less power to operate since the motor of the vacuum pump does not have to pull section from all sections of the platen if all sections of the platen are not used or covered by print media. This platen is designed to use less electricity and selectively provide vacuum to desired chambers of the platen.
The present invention also provides the advantage of being quieter to operate which provides an environment which is safer for employees and will reduce the hazards of hearing loss due to loud noises associated with the suction on the platen.
The present invention provides an advantage of being able to accommodate multiple print sizes of print media with an increased versatility over commercial units.
With reference to the figures,
The tray can include one or more mounting feet to hold the tray flat to a frame of a printer or photographic processing unit.
One or more vacuum ports can be formed in the vacuum platen tray 10 to control vacuum to the tray.
The vacuum platen device can include numerous mounting bosses 26, 28, 30, 32, 34, 36, 37, 39 and 41 (which is not shown) located in the base of the tray. The mounting bosses 26, 28, 30, 32, 34, 36, 37, 39 and not shown 41, are used to connect the plate which is depicted in
The plate 50 is preferably made out of aluminum and is attached to the top of the vacuum platen tray. The plate can be made of coated metal, or it can be a laminate. Typically, the plate 50 attaches to the platen tray 10 using mounting bosses 26, 28, 30, 32, 34, 36, 37, 39 and 41 using screws which are not shown to hold the plate 50 onto the platen tray 10, as depicted in
The plate 50 includes a plurality of slots that are aligned with the chambers. In
The slots formed in parallel rows and are positioned to give maximum flexibility to print on various sizes of print media or cut sheets. The length of the slots can range from approximately 2 inches for short slots to about 4.5 inches for long slots. Some slots in one row, as shown in
The spacing between the parallel rows of the slots can be uniform or can vary between rows. For example, between a first and second row, the space width can be approximately 2 inches; between the second and third row, the space width can be 1 inch; and between the third and fourth row, the space width can be 2.5 inches. The spacing of the rows further facilitates the vacuum platen tray 10 to accommodate many widths of print media.
In
The photographic processor 58, as depicted in
In the exposure section 65, the first side of the print media 62 is exposed to an exposing mechanism. The exposed print media is positioned so that the first side is up and passes through the exposing position 72. The print media is conveyed first side down along a second conveying path 77. The conveying paths 70 and 77 can be slanted. Typically, the first conveying path 70 is above the second conveying path 77.
From the exposure section 65, the exposed print media 62 goes through a chemical development section 80. The chemical development section 80 receives the exposed print media 62 with the first side down from the exit of the exposure section. After passing through the chemical development section 80, the exposed print media is passed to a finishing section 82. In the finishing section 82, the exposed print media 62 can go through at least a drying operation and a sorting operation.
The print media 62 of this particular embodiment can be a photographic member provided in web form. In another embodiment, the media can be cut after leaving the supply area and prior to reaching the exposing section using known cutting arrangements. The photographic processor is adapted to transport and process cut sheets as well as web media. The present embodiments are not limited to processing cut sheets. Other types of media, such as thin polymer films for bread bags and materials other than paper, can be used in this process. One of the features of these embodiments is that various sizes of media and various types of media can be disposed in each magazine and used with these devices.
The vacuum platen device can additionally include a controller to operate the activity in each section and shuttle optimally. Although the vacuum assembly or device is shown as being located at the exposure section, the present invention is not limited to this location. The vacuum assembly or device in accordance with the present invention can be positioned at any location within a printer or processor where it is desired to precisely hold and/or transport different size media.
As depicted in
The holes in the belt 86 can have a diameter ranging from a diameter from 1/16 to ¼ inches, preferably about ⅛ inch. In a preferred embodiment, the holes are disposed in parallel lines approximately ½ inch apart lengthwise around the belt 86.
The belt 86 is preferably a woven material, such as a synthetic rubber. In a preferred embodiment, black neoprene rubber or an impregnated woven endless polyester fiber can be used to construct the endless belt 86. Springs can be used to keep the belt 86 tensioned around the vacuum platen tray 10.
The vacuum platen may include a filter configured to collect debris from the airflow in order to keep debris from clogging the ports. In such cases, the filter can be configured to reduce an acoustic energy level of the airflow thereby helping to quiet the vacuum platen during use thereof in the printing device. While use of any filter material that provides an adequate filtering and pressure drop can be employed with the present embodiments, the preferred filter materials include polypropylene, cotton, polyester, PTFE, cellulose or the like paper, or sintered materials such as of plastic or metals.
The embodiments have 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 scope of the embodiments, especially to those skilled in the art.
