Patent Application
20100320677
This disclosure relates to a printing apparatus, and more specifically, to an improved rigid plate belt and drive system for use in an ink jet printing apparatus.
Typically, vacuum transport systems are disposed within a copier or printer between a photoreceptor and the fuser rolls and comprises a flexible belt which is entrained about two or more rollers. This belt typically includes a number of small holes therein. Disposed inside the belt is a vacuum plenum having a slotted plenum plate thereover with the vacuum plenum being actuated by a vacuum blower to thereby draw air through the holes in the belt, particularly in the area where a sheet moving in a process direction is passing over the belt. Thus, the vacuum plenum holds a sheet against the outer surface of the belt while the belt moves the sheet, for example, from the photoreceptor toward the nip of the fuser rolls. For traditional vacuum transport implementations increasing cut sheet media sizes can cause decreased air flow losses and increasing static vacuum pressures on the sheet and belt acting against the stationary plenum plate. This causes non-useful high friction between the belt and the slotted plenum plate. This arrangement also has the added problem of keeping the moving holes of the belt always exposed to the rigid plenum slots. Additionally, the requirement for a consistent flat belt that is consistently flat under all the print heads of an ink jet printing system is a problem with tight specifications.
In U.S. Pat. No. 6,505,030 a vacuum transport is shown that allows for varying air pressure on a sheet responsible to sensed sheet parameters, such as, weight and size with the use of multiple plates in a vacuum plenum and a sensor. This patent is included in its entirety herein by reference.
In answer to these problems and disclosed herein is an improved vacuum transport that includes a segmented, rigid or solid articulated belt combined with a central vacuum plenum connected to each segment of the belt. By using a rigid segmented belt with a vacuum plenum connected to each segmented belt section, and driving the belt with a device positioned on the top side of the belt, the heretofore-mentioned drag friction is eliminated by reducing the force necessary to move belt with media thereon while simultaneously improving the motion quality of the move by driving the articulated rigid belt from the top side of the belt in a flat section.
Various of the above-mentioned and further features and advantages will be apparent to those skilled in the art from the specific apparatus and its operation or methods described in the example(s) below, and the claims. Thus, they will be better understood from this description of these specific embodiment(s), including the drawing figures (which are approximately to scale) wherein:
While the disclosure will be described hereinafter in connection with a preferred embodiment thereof, it will be understood that limiting the disclosure to that embodiment is not intended. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the disclosure as defined by the appended claims.
The disclosure will now be described by reference to a preferred embodiment ink jet printing apparatus that employs an improved interconnected rigid sectioned vacuum belt for transport and a high motion quality drive mechanism.
For a general understanding of the features of the disclosure, reference is made to the drawings. In the drawings, like reference numerals have been used throughout to identify identical elements.
Referring now to printer 10 in
The ink jet printer 10 includes a first conveyance path 18 that extends from the leading end portion of the paper supply of the paper supply cassette 12 and leads to a recording section 16, which conducts image recording on the paper P. Plural fist conveyance roller pairs 20 that constrain and convey the paper P to the recording section 16 are disposed on the first conveyance path 18.
The ink jet printer 10 also includes a second conveyance path 24 that extends upward from the recording section 16 and leads to a paper discharge tray 22, which accommodates the paper P on which an image has been recorded. Plural secondary roller pairs 26 that convey the paper P to the paper discharge 22 are disposed on the second conveyance path 24. An inverse conveyance path 36 for conducting two sided printing connects the second conveyance path 24 to the first conveyance path 18.
In operation, the paper P is removed from the paper supply cassette 12 by the feed roll 14, conveyed on the first conveyance path 18 by the plural conveyance roller pairs 20, and fed to the recording section 16, where image recording is conducted. When an image has been recorded on the paper P, the paper P is conveyed on the second conveyance path 24 by the plural conveyance roller pairs 26 and discharged into the paper discharge tray 22. When two-sided printing is to be conducted, an image is first recorded on one side of the paper P, and then the paper P is inverted at the junction 35 of paths 24 and 36 and is conveyed from the second conveyance path 24 to the first conveyance path 18 via the inverse conveyance paper path 36 and is again fed to the recording section 16, where image recording is conducted on the other side of the paper P. Thus, successive image recording is conducted.
In accordance with the present disclosure, the recording section 16 includes an endless, interconnected, rigid, segmented or sectioned vacuum conveyor belt 32 that includes a number of small holes 33 shown in
An ink jet recording head 34 is disposed above the vacuum belt 32. The ink jet recording head 34 is configured to be long, such that its effective recording area is approximately equal to or greater than the process direction width of the paper P. The ink jet recording head 34 includes at least four inkjet recording heads 34C, 34M, 34Y and 34K, which respectively, correspond to the four colors cyan (C), magenta (M), yellow (Y) and black (K). The ink jet recording heads 34C, 34M, 34Y and 34K are disposed along the conveyance direction; thus, the ink jet recording head 34 can record a full-color image.
The ink jet recording head 34 faces a flat portion 32F of the conveyance vacuum belt 32, and this facing area serves as an ejection areas to which ink droplets are ejected from the ink jet recording head 34. The paper P conveyed on the first conveyance path 18 is retained and held flat to vacuum belt 32 by force of vacuum and sent to the ejection region, where the ink droplets corresponding to the image are ejected from the ink jet recording head 34 and onto the paper P in a state where the paper P faces the ink jet recording head 34.
Ink tanks 40C, 40M, 40Y and 40K, which supply the inks to the inkjet recording heads 34C, 34M, 34Y and 34K are disposed above the ink jet recording head 34.
The ink jet recording heads 34C, 34M, 34Y and 34K are connected to a recording head controller 50. The recording head controller 50 controls the ink jet recording head 34 by determining the ejection timing of the ink droplets and the ink ejection ports or nozzles to be used, in accordance with image information, and inputting a drive signal to the ink jet recording heads 34C, 34M, 34Y and 34K.
In accordance with the present disclosure and shown in
As shown in
High motion quality drive mechanisms for segmented, rigid plate, vacuum transport 32 are shown in
In
Alternatively, vacuum plenum 30 could be positioned over the outboard side of vacuum belt 32 or within vacuum belt 32, if desired. Also, the high motion quality top drive mechanism of the present disclosure while preferably positioned to drive the vacuum belt from the outboard side of the belt will work equally well if placed on the inboard side of the belt.
It should now be understood that a vacuum transport system has been disclosed that promotes depth of focus control between a media print plane and ink jet heads of about ±0.1 mm and comprises an interconnected, rigid, sectioned vacuum belt for media transport through an imaging zone of an ink jet printer. Each section or segment of the vacuum belt has its own vacuum plenum and source of vacuum. The vacuum belt is driven by a drive mechanism that is positioned on top of one of the segments of the vacuum belt in an area where the segments are in a horizontal plane in order to eliminate ‘chordal effects’ and thereby remove image quality as a concern. While the disclosed vacuum transport system is shown used for transporting cut sheet media, it could also be used, for example, with a larger scale corrugated ink jet printing system.
The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others. Unless specifically recited in a claim, steps or components of claims should not be implied or imported from the specification or any other claims as to any particular order, number, position, size, shape, angle, color, or material.
