Abstract:
A cleaning system for an inkjet printhead is disclosed. The cleaning system has a wiper and a scraper. The wiper has a wiper blade that has a top edge that is scraped by the bottom edge of the scraper when the wiper moves past the scraper. The top edge of the wiper blade forms and angle with respect to the bottom edge of the scraper.

Description:
BACKGROUND 
       [0001]    The sound generated by inkjet printers from the time a print job is started to the time the job is completed generates different acoustic experiences for the user. In general, the sounds produced during printing are deemed more acceptable than the sounds produced before or after printing. These non-printing sounds are mostly attributed to the noise generated by a wiper as it traverses across the inkjet printhead and the scraper. Wipers are used to clean the nozzles in the inkjet printhead between print jobs. Scrapers are used in an inkjet service station to maintain the cleanliness of the wipers. The wipers are bent as they are cleaned by the scrapers. Noise is generated when the wiper blades are released from the scraper as wiper passes under the scraper. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0002]      FIG. 1A  is an isometric top view of a wiper  100  in an example embodiment of the invention. 
           [0003]      FIG. 1B  is an isometric top view of a scraper  130  in an example embodiment of the invention. 
           [0004]      FIG. 2A-2C  is a plurality of side views showing a traditional wiper/scraper design. 
           [0005]      FIG. 3  is a top view of a scraper/wiper design  300  in an example embodiment of the invention. 
           [0006]      FIG. 4  is a top view of a wiper  400  in an example embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0007]      FIGS. 1-4 , and the following description depict specific examples of the invention. For the purpose of teaching inventive principles, some conventional aspects have been simplified or omitted. Those skilled in the art will appreciate variations from these examples that fall within the scope of the invention. The features described below can be combined in various ways to form multiple variations of the invention. As a result, the invention is not limited to the specific examples described below, but only by the claims and their equivalents. 
         [0008]      FIG. 1A  is an isometric top view of a wiper  100  in an example embodiment of the invention. Wiper  100  comprised base  104  and wiper blade  106 . Wiper blade  106  has a top edge  102  running along the length L of wiper blade  106 . Wiper blade  106  is fabricated from a flexible material.  FIG. 1B  is an isometric top view of a scraper  130  in an example embodiment of the invention. Scraper  130  comprised base  136  and scraper blade  132 . Scraper blade  132  has a bottom edge  134  running along the length of scraper blade  132 . Scraper blade  132  is fabricated from a stiff material. 
         [0009]    In a traditional wiper/scraper design, the long top edges of the wiper blades and bottom edges of the scraper are parallel with each other and the scrapers travel perpendicular to the long edges.  FIG. 2  is a plurality of side views showing a traditional wiper/scraper design. In  FIG. 2A  wiper  100  is positioned to the left of scraper  202 . The wiper blade  106  is parallel to the scraper blade  206 . Scraper  202  is configured to move past wiper  100  in the direction of arrow  204 . The bottom edge of scraper blade  206  extends downwards below the top of wiper blade  106 . As scraper  202  moves past wiper blade  106 , the bottom edge of scraper blade  206  hits and deflects the top of wiper blade  106  (see  FIG. 213 ). Because the wipers and scrapers are parallel with each other the full length of the wiper blade is engaged with the scraper as the scraper moves over the wiper. As the scraper moves past the wiper, the full length of the wiper is released (see  FIG. 2C ) essentially at the same time. Because the full length of the wiper blades is released at the same time, a loud slapping sound can be generated. In other example embodiments, the scraper may be stationary and the wiper will move past the scraper. 
         [0010]    In one example embodiment of the invention, the scraper edge is positioned at an angle with respect to the wiper blade. This angled approach allows for a delayed and staggered released of the wiper blade from the scraper, thus reducing the noise generated.  FIG. 3  is a top view of a scraper/wiper design  300  in an example embodiment of the invention. Scraper/wiper design  300  comprises two wipers  100  and two scrapers  202 . In one example embodiment of the invention, one wiper may be for a color printhead and the other wiper may be for a black printhead. The two wipers  100  are spaced apart with the wiper blades  106  aligned parallel to one another along the X axis. In one example embodiment of the invention, the two wiper blades  106  may be offset from each other by distance d. 
         [0011]    The two scrapers  202  are positioned side by side and are aligned with the wipers in the x axis. The two wipers are configured to move along the Y axis (as shown by arrow  204 ) such that the wipers pass under the scraper blades  206 . Each of the scrapers  202  has a scraper blade  206  formed at an angle α with respect to the wiper blades  106 . In one example embodiment of the invention, one scraper blade will make a positive angle α with respect to the wiper blades, and the other scraper blade will make a negative angle α with respect to the wiper blades. In this way the scraper blades will be angled such that the scraper blades are not parallel. Using scraper blades angled in opposite directions will help to minimize any force generated in the X axis as the scraper blades  206  scrape the wiper blades  106 . 
         [0012]    Because the scraper blades are angled with respect to the wiper blades, the wiper blades will be not be release by the scrapers along the full length L of the wiper blades at the same time. This will reduce the amount of noise created as the wiper blades are released. In one example embodiment of the invention, the angle α is between 0.5 and 15 degrees. In another example embodiment of the invention, angle α is 5 degrees. 
         [0013]    When distance d is non-zero and the wiper blades are offset from one another, one wiper blade will be completely released before the other wiper blade is completely released. This will also help to minimize the nose created when the wiper blades are released. In one example embodiment of the invention, the distance d is between 0.5 and 20 mm. In another example embodiment of the invention, distance d is 2.1 mm. In some example embodiments of the invention, the wiper blades may not be offset from one another, but the leading edge of the two scrapers may be offset from one another. This would have the same effect as having the wiper blades offset from one another. 
         [0014]    In some example embodiments of the invention, each wiper may have multiple wiper blades.  FIG. 4  is a top view of a wiper  400  in an example embodiment of the invention. Wiper  400  has multiple wiper blades  406 . In one example embodiment of the invention, one scraper blade will be used to scrape all the different wiper blades. In other embodiments, different scraper blades may be used for each wiper blade.