Patent Publication Number: US-2007103533-A1

Title: Combination of monochromatic-printing and color-printing device

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to an image-printing device, and more particularly to a combination of monochromatic-printing and color-printing device.  
      2. The Related Art  
      Generally, printers are approximately divided into dot-matrix printers, thermal printers, inkjet printers and laser printers. The inkjet printer and the laser printer occupy the most market.  
      As is well known, the cost of printing a monochromatic page by the inkjet printer is higher than that by the laser printer, while the cost of printing a color page by the laser printer is far higher than that by the inkjet printer, and the color printing quality by the laser printer is worse than that by the inkjet printer. Therefore, a printing device with combination of inkjet printer and laser printer is needed to facilitate users selecting the cheapest and the most quality method for a printing job.  
      U.S. Pat. No. 6,582,039 issued on Jun. 24, 2003 by Johnson et al. provides a combination color inkjet and laser image-printing device. The conventional image-printing device comprises a laser print engine, an inkjet print engine and a paper-picking device. The paper-picking device comprises a first paper-picking mechanism and a second paper-picking mechanism. The first paper-picking mechanism feeds print media from the single supply of a print medium to a first transport path where the laser print engine is disposed, and the second paper-picking mechanism feeds print media from the single supply of print medium to a second transport path where the inkjet print engine is disposed.  
      Although the conventional image-printing device can provide both laser printing and inkjet printing functions, however it has two paper-picking mechanism and two paper transport paths. So the conventional image-printing device is too complex and too bulky to satisfy the market need of small-sized printers.  
     SUMMARY OF THE INVENTION  
      An object of the present invention is to provide a combination of monochromatic-printing and color-printing device comprising a feeding tray for supplying print media, an output tray in which the print media printed in a print job are interleaved and collated, and a paper transport path connecting the feeding tray and the output tray. The paper transport path has a plurality of driving rollers for transporting the print media from the feeding tray to the output tray, a monochromatic print unit for monochromatic printing and a color print unit for color printing disposed thereat. At least one of the monochromatic print unit and the color print unit is controlled to be in work corresponding to a print job.  
      As stated, the combination of monochromatic-printing and color-printing device realizes the objective of monochromatic-printing and color-printing by disposing the monochromatic and color print units in a single paper transport path, thus the printer is simple and can be miniaturized to satisfy the market need of small-sized printers.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The present invention will be apparent to those skilled in the art by reading the following description of preferred embodiments thereof, with reference to the attached drawings, in which:  
       FIG. 1  is a schematic view of a first embodiment of a combination of monochromatic-printing and color-printing device according to the present invention;  
       FIG. 2  is a schematic view of a second embodiment of a combination of monochromatic-printing and color-printing device according to the present invention;  
       FIG. 3  is a schematic view of a third embodiment of a combination of monochromatic-printing and color-printing device according to the present invention;  
       FIG. 4  is a schematic view of a fourth embodiment of a combination of monochromatic-printing and color-printing device according to the present invention;  
       FIG. 5  is a schematic view of a fifth embodiment of a combination of monochromatic-printing and color-printing device according to the present invention;  
       FIG. 6  is a schematic view of a sixth embodiment of a combination of monochromatic-printing and color-printing device according to the present invention;  
       FIG. 7  is a schematic view of the sixth embodiment of the combination of monochromatic-printing and color-printing device in another state;  
       FIG. 8  is a schematic view of a seventh embodiment of a combination of monochromatic-printing and color-printing device according to the present invention;  
       FIG. 9  is a schematic view of the seventh embodiment of the combination of monochromatic-printing and color-printing device in another state;  
       FIG. 10  is a schematic view of an eighth embodiment of a combination of monochromatic-printing and color-printing device according to the present invention; and  
       FIG. 11  is a schematic view of the eighth embodiment of the combination of monochromatic-printing and color-printing device in another state. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Referring to FIGS.  1  to  11 , a combination of monochromatic-printing and color-printing device  100  comprises a feeding tray  2  for supplying print media, an output tray  3  in which the print media printed in a print job are interleaved and collated, and a paper transport path  1  connecting the feeding tray  2  and the output tray  3 . The print media are transported forwards in the paper transport path  1  along the transport direction of the print media (the arrowed direction shown in drawings). The paper transport path  1  has a plurality of driving rollers for transporting the print media from the feeding tray  2  to the output tray  3 , a monochromatic print unit for monochromatic printing and a color print unit for color printing disposed thereat. The color print unit can be disposed at back or front of the monochromatic print unit. The monochromatic print unit and the color print unit may be an inkjet print unit, a thermal print unit or others. In all embodiments of the present invention, the monochromatic print unit is a laser print unit, and the color print unit is an inkjet print unit.  
      Referring to  FIG. 1 , in a first embodiment of the present invention, the paper transport path  1  is horizontally arranged. The laser print unit comprises a photo conductor  40  lying above the paper transport path  1 . The inkjet print unit lies in front of the laser print unit and comprises an inkjet printhead  51  and a ratchet  52 . The ratchet  52  lies in front of the inkjet printhead  51 . The inkjet printhead  51  lies above the paper transport path  1 .  
      The driving rollers comprise a set of first driving rollers  61  and a set of second driving rollers  62 . The first driving rollers  61  lying at rear end of the paper transport path  1  are adapted to transport the print media from the feeding tray  2  to the paper transport path  1 . The second driving rollers  62  lying between the laser print unit and the inkjet print unit are adapted to transport the print media ahead along the paper transport path  1 .  
      Referring to  FIG. 1  again, in use, firstly, the print media are transported from the feeding tray  2  to the paper transport path  1  by the first driving rollers  61 .  
      When printing a monochromatic page, firstly, control the laser print unit be in work and the inkjet print unit be out of work. While, a print medium passing the photo conductor  40  is printed into a monochromatic page by the laser print unit. Lastly, the monochromatic page is transported to the output tray  3  by the second driving rollers  62  and the ratchet  52 .  
      When printing a color page, firstly, control the laser print unit be out of work and the inkjet print unit be in work. While, a print medium passing the photo conductor  40  is not printed by the laser print unit and then is transported to the second driving rollers  62 . To follow, the print medium is transported to pass the inkjet printhead  51  by the second driving rollers  62 . Simultaneously, the print medium passing the inkjet printhead  51  is printed into a color page and then is transported to the output tray  3  by the ratchet  52 .  
      When printing a monochromatic and color page, firstly, control the laser print unit and the inkjet print unit be both in work. While, a print meduim passing the photo conductor  40  is printed into a monochromatic page by the laser print unit and then is transported to the second driving rollers  62 . To follow, the monochromatic page is transported to pass the inkjet printhead  51  by the second driving rollers  62 . Simultaneously, the monochromatic page passing the inkjet printhead  51  is printed into a monochromatic and color page and then is transported to the output tray  3  by the ratchet  52 .  
      Referring to  FIG. 2 , in a second embodiment of the present invention, the paper transport path  1  appears U-shaped. The inkjet print unit lies in front of the laser print unit along the transport direction of the print media. The inkjet printhead  51  of the inkjet print unit lies at one side of the paper transport path  1 , and the photo conductor  40  of the laser print unit lies at the other side of the paper transport path  1 .  
      Referring to  FIG. 3 , in a third embodiment of the present invention, the paper transport path  1  appears U-shaped. The inkjet print unit lies in front of the laser print unit along the transport direction of the print media. The inkjet printhead  51  of the inkjet print unit and the photo conductor  40  of the laser print unit lies at the same side of the paper transport path  1 .  
      Referring to  FIG. 4 , in a fourth embodiment of the present invention, the paper transport path  1  appears ladder-shaped. The inkjet print unit lies in front of the laser print unit along the transport direction of the print media. The inkjet printhead  51  of the inkjet print unit lies at one side of the paper transport path  1 , and the photo conductor  40  of the laser print unit lies at the other side.  
      Referring to  FIG. 5 , in a fifth embodiment of the present invention, the paper transport path  1  appears horizontal U-shaped. The inkjet print unit lies at back of the laser print unit along the transport direction of the print media. The inkjet printhead  51  of the inkjet print unit and the photo conductor  40  of the laser print unit lies at the same side of the paper transport path  1 .  
      The other structure and the process of use in the above-mentioned second to fifth embodiment is the same to the first embodiment, thus will not be referred.  
      As shown in  FIG. 6 , in the sixth embodiment of the present invention, the paper transport path  1  is horizontally arranged. The inkjet print unit lies in front of the laser print unit along the transport direction of the print media.  
      The laser print unit comprises a photo conductor  40 , a shelter plate  41  and a movable member  42 . The photo conductor  40  and the shelter plate  41  are disposed in opposition to each other along the vertical of the transport direction of the print media. The photo conductor  40  lies above the paper transport path  1 , the shelter plate  41  lies below the paper transport path  1 . The movable member  42  is at the same side of the paper transport path  1  with the shelter plate  41  and lies at back of the shelter plate  41  along the transport direction of the print media. The movable member  42  further comprises an axle  43  and a movable shaft  44 . The movable shaft  44  connects to the axle  43  and rotates around the axle  43 .  
      The inkjet print unit comprises an inkjet printhead  51  and a ratchet  52 . The ratchet  52  lies in front of the inkjet printhead  51 , the inkjet printhead  51  lies above the paper transport path  1 .  
      The driving rollers comprise a set of first driving rollers  61  and a set of second driving rollers  62 . The first driving rollers  61  lying at back end of the paper transport path  1  are adapted to transport the print media from the feeding tray  2  to the paper transport path  1 . The second driving rollers  62  lying between the laser print unit and the inkjet print unit are adapted to transport the print media ahead along the paper transport path  1 .  
      As shown in  FIG. 6  and  FIG. 7 , in use, firstly, the print media are transported from the feeding tray  2  to the paper transport path  1  by the first driving rollers  61 .  
      Referring to  FIG. 6 , when printing a monochromatic page, firstly, control the inkjet print unit be out of work. While, the movable member  42  lies in the first movable position, the free end of the movable shaft  44  is on the same horizontal plane with the shelter plate to support a print medium be transported on the paper transport path  1 . After passing the movable member  42 , the print medium passes through between the photo conductor  40  and the shelter plate  41 . Meanwhile, the print medium passing the photo conductor  40  is printed into a monochromatic page by the laser print unit. Lastly, the monochromatic page is transported to the output tray  3  by the second driving rollers  62  and the ratchet  52 .  
      Referring to  FIG. 6  again, when printing a monochromatic and color page, firstly, control the inkjet print unit be in work. A print medium being printed into a monochromatic page by the laser print unit is transported to the second driving rollers  62  and then is transported to pass the inkjet printhead  51  by the second driving rollers  62 . Meanwhile, the monochromatic page passing the inkjet printhead  51  is printed into a monochromatic and color page and then is transported to the output tray  3  by the ratchet  52 .  
      As shown in  FIG. 7 , when printing a color page, firstly, control the inkjet print unit be in work. While, the movable shaft  44  of the movable member  42  rotates around the axle  43  and is fixed at position parallel to the shelter plate  41  to enable the movable member  42  be in the second movable position. Then, the print medium deviates downwards from the paper transport path  1  and passes through under the shelter plate  41 . Thus, the print medium detours the photo conductor  40  so that the laser print unit does not print the print medium. To follow, the print medium is transported to the second driving rollers  62  and passes the inkjet printhead  51  by the second driving rollers  62 . While, the print medium is printed into a color page by the inkjet print unit. Then, the color page is transported to the output tray  3  by the ratchets  52 .  
      Referring to  FIG. 8 , in a seventh embodiment of the present invention, the paper transport path  1  appears U-shaped. The inkjet print unit lies at back of the laser print unit along the transport direction of the print media. The inkjet printhead  51  and the photo conductor  40  are at the same side of the paper transport path  1 . The movable member  42  of the laser print unit lies at back of the photo conductor  40  and the shelter plate  41 . The movable member  42  and the photo conductor  40  are at the same side of the paper transport path  1 .  
      Referring to  FIG. 8  and  FIG. 9 , in use, firstly, the print media is transported to the paper transport path  1 .  
      As shown in  FIG. 8 , when printing a monochromatic page, firstly, control the inkjet print unit be out of work. While, the free end of the movable shaft  44  slopes to the paper transport path  1  to enable the movable member  42  be in the first movable position, therefore a print medium passes through between the photo conductor  40  and the shelter plate  41  for being monochromatically printed.  
      Referring to  FIG. 8  again, when printing a monochromatic and color page, firstly, control the inkjet print unit be in work. While, a print medium passes below the inkjet printhead  51  for being color printed, then passes through between the photo conductor  40  and the shelter plate  41  for being monochromatically printed.  
      Referring to  FIG. 9 , when printing a color page, firstly, control the inkjet print unit be in work. While, a print medium passes below the inkjet printhead  51  for being color printed, then, the movable shaft  44  rotates backwards around the axle  43  and is fixed at position vertical to the transport direction of the print media. While, the free end of the movable shaft  44  moves to the side of the shelter plate  41  to enable the movable member  42  be in the second position. While, the color page passes the movable shaft  44  and is propped by the movable shaft  44  to pass from the outside of the shelter plate  41 . Thus the color page detours the photo conductor  40  so that the laser print unit does not print the page.  
      Referring to  FIG. 10  and  FIG. 11 , the difference between an eighth embodiment and the seventh embodiment of the present invention lies in: the inkjet print unit lies in front of the laser print unit along the transport direction of the print media, the inkjet printhead  51  of the inkjet print unit lies at one side of the paper transport path  1 , the photo conductor  40  of the laser print unit lies at the other side of the paper transport path  1 . The use process of the present embodiment is similar to the seventh embodiment of the present invention.  
      As stated, the combination of monochromatic-printing and color-printing device  100  realizes the objective of monochromatic-printing and color-printing by disposing the monochromatic and color print units in a single paper transport path  1 , thus the printer can be miniaturized, therefore the market need of the small-sized printer is satisfied.