Patent Publication Number: US-6669328-B2

Title: Wiper for avoiding ink residues adhering on side surfaces of a print head

Description:
This application incorporates by reference of Taiwan application Ser. No. 090207391, filed May 7, 2001. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates in general to a wiper for cleaning the nozzle surface, and more particularly to a wiper for avoiding ink residues on side surfaces of the print head. 
     2. Description of the Related Art 
     In the technology booming age, the ink-jet machine, such as the ink-jet printer or inkjet copier, has grown in popularity and thus becomes indispensable for people&#39;s life. For example, the ink-jet printer is capable of printing the document by linking the ink-jet printer and the computer so as to improve work efficiency. 
     The ink required by the ink-jet machine is contained in the cartridge while the print head is positioned at the bottom of the cartridge. The print head jets small ink droplets onto the paper through the nozzle surface of the print head to create an output image. Accordingly, the ink residues adhere to the nozzle surface. If the ink residues are accumulated without cleaning, the dried ink residues are possible to form blockages in the print head or smudge the paper, which might decrease the printing quality. Therefore, the printing work shall be halted for wiping the ink residues on the nozzle surface in the cleaning area inside the ink-jet machine whenever the printing has performed several times. The following description takes an ink-jet printer as an example of the ink-jet machine. 
     Referring to FIG. 1A, it shows the top view of a conventional ink-jet printer. The ink-jet printer  100  comprises a casing  101 , print head  102 , and cleaning area  106 . The print head  102  inside the casing  101  is driven by a driving device (not shown in FIGS) and moves back and forth on the paper to be printed  104  along the direction of the arrow sign  150  of FIG.  1 A. The print head  102  jets ink droplets onto the paper to be printed  104  and the paper to be printed  104  moves upward along the direction of the arrow sign  160  of FIG. 1A to complete the printing work. The cleaning area  106  includes a wiper, cap, and blotter. The wiper is for wiping the ink residues on the surface of the print head  102 . The cap is the cover of the print head  102  for preventing the ink from being dried to form blockages in the print head  102  while the print head is homed at the cleaning area  106 . The blotter is for blotting out the ink splashed during the cleaning. 
     The structure of the wiper  130  in the cleaning area  106  is disclosed in U.S. Pat. No. 5,612,722 by Monty L. Francis, Edmund H. James, III, and Donald N. Spitz. Lateral views of the print head and the wiper of FIG. 1A are shown in FIG.  1 B. The wiper  130  includes a main body  108  and a base  118 . The main body  108  has a supporting portion  109 , flexible portion  112 , and wiping portion  114 . The supporting portion  109  has a groove  116  for the insertion of the protruding end  115  of the supporting portion  109  so that the main body  108  can be mounted on the base  118 . The flexible portion  112  is disposed upon the supporting portion  109 , the wiping portion  114  is upon the flexible portion, and therefore the supporting portion  109 , flexible portion  112 , and wiping portion  114  are in one unity. 
     Please refer to FIG. 1C, the enlarged view of the wiping portion  114  of FIG. 1B is shown. The wiping portion  114  has a coplanar surface  120 , wiping ends  122   a  and  122   b . The wiping ends  122   a  and  122   b  are disposed at two sides of the coplanar surface  120  and form two acute angles respectively. The coplanar surface  120  is level with the wiping ends  122   a  and  122   b . Besides, the plane formed by the coplanar surface  120  and the wiping ends  122   a  and  122   b  is higher than the plane level L of the nozzle surface  110 . When the wiper  130  is stationary and the print head  102  moves back and forth along the direction of the arrow sign  170  of FIG. 1B, the wiping ends  122   a  and  122   b  contact the side surfaces  102   a  and  102   b  of the print head  102  respectively. The flexible portion  112  bends down while the print head  102  pushes the wiping portion  114 . The wiping ends  122   a  and  122   b  touches the nozzle surface  110  and then the ink residues on the nozzle surface  110  is removed as the relative motion between the print head  102  and the wiper  130  proceeds. 
     Referring to FIGS. 2A to  2 G, it schematically illustrates the wiping sequences of the wiper of FIG. 1B for wiping the ink residues. Referring first to FIG. 2A, as the print head  102  approaches the wiping end  122   a  along the direction of the arrow sign  180  of FIG. 2A, the side surface  102   a  of the print head  102  subsequently touches and pushes the wiping end  122   a  so that the flexible portion  112  bends to the right. As shown in FIG. 2B, the print head  102  proceeds to move along the direction of the arrow sign  180  of FIG.  2 B. Subsequently, the wiping end  122   a  touches the nozzle surfaces  110  and removes the ink residue  111  as the relative motion between the print head  102  and the wiping end  122   a  proceeds. Referring to FIG. 2C, the wiping end  122   a  comes off the nozzle surface  110  and the ink residue  111  adheres to the left side of the wiping end  122   a . Meanwhile, the flexible portion  112  recovers to the former shape and the plane formed by the coplanar surface  120  and the wiping ends  122   a  and  122   b  is higher than the plane level L of the nozzle surface L again. 
     On the other hand, when the print head  102  approaches the wiping end  122   b  along the direction of the arrow sign  190  of FIG. 2C, the side surface  102   b  of the print head  102  subsequently touches and pushes the wiping end  122   b  so that the flexible portion  112  bends to the left as shown in FIG.  2 D. The print head  102  proceeds to move along the direction of the arrow sign  190  of FIG.  2 D and the wiping end  122   b  subsequently touches the nozzle surfaces  110  and performs wiping. Once the wiping end  122   b  comes off the nozzle surface  110 , the flexible portion  112  recovers to the former shape and the ink residue  111  remains adhering to the left side of the wiping end  122   a  as shown in FIG.  2 E. At this time, if the print head  102  approaches the wiping end  122   a  along the direction of the arrow sign  180  of FIG. 2E again, the side surface  102   a  of the print head  102  subsequently touches the wiping end  122   a  and the ink residue  111  as shown in FIG. 2F As shown in FIG. 2G, the ink residue  111  is shifted from the left side of the wiping end  122   a  to the side surface  102   a  of the print head  102 . 
     Conventionally, the wiping ends  122   a  and  122   b  of the main body  108  are two sides of the coplanar surface  120 . The coplanar surface  120  is level with the wiping ends  122   a  and  122   b  and the wiping force is generated by the deformation of the main body  108  due to the relative motion between the print head  102  and the wiping ends  122   a  and  122   b . The ink residue  111  on the nozzle surface  110  is removed by the wiping end  122   a  and  122   b  and finally adheres to the side surface  102   a  and  102   b  of the print head  102 . Consequently, when the cleaning completes and the print head  102  proceeds to print, the ink residue  111  adheres to the side surface  102   a  and  102   b  of the print head  102  might fall to the paper to be printed  104 . The paper is smudged with the ink residues and the printing quality is therefore decreased. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the invention to provide a wiper for avoiding ink residues on side surfaces of the print head. It keeps side surfaces of the print head clean and ensures the printing quality. 
     The invention achieves the above-identified objects by providing a wiper for avoiding ink residues on side surfaces of a print head, the wiper comprises a main body and a base. The main body comprises a supporting portion, flexible piece, and wiping portion. The flexible piece is disposed upon the supporting portion and the wiping portion is disposed upon the flexible piece. The wiping portion has a wiping end and a contacting end. The wiping end extends from one side of the wiping portion while the contacting end is positioned on the top of the wiping portion. Before the print head contacts the contacting end, the contacting end is higher than the nozzle surface and the wiping end is lower than the nozzle surface. After the print head contacts the contacting end, the flexible piece bends down due to the relative motion between the print head and the wiper so that the contacting end is lower than the nozzle surface and the wiping end contacts the nozzle surface for wiping the ink residue on the nozzle surface. 
     Other objects, features, and advantages of the invention will become apparent from the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A (Prior Art) is the top view of a conventional ink-jet printer; 
     FIG. 1B shows lateral views of the print head and the wiper of FIG. 1A; 
     FIG. 1C shows the lateral view of the wiping portion of FIG. 1B; 
     FIGS.  2 A˜ 2 G schematically illustrates the wiping sequences of the wiper of FIG. 1B for wiping the ink residues; 
     FIG. 3A is an exploded view of the wiper for avoiding ink residues on side surfaces of the print head according to the first embodiment of the invention; 
     FIG. 3B is a perspective view of the wiper for avoiding ink residues on side surfaces of the print head according to the first embodiment of the invention; 
     FIG. 3C is a lateral view of the wiper for avoiding ink residues on side surfaces of the print head according to the first embodiment of the invention; 
     FIG. 3D is a lateral view of the wiping portion of FIG. 3C; 
     FIGS.  4 A˜ 4 F schematically illustrates the wiping sequences of the wiper of FIG. 3C for wiping the ink residues; 
     FIG. 5A shows a wiper of FIG. 3C added with two wiping ends; 
     FIG. 5B is a lateral view of the wiping portion of FIG. 5A; 
     FIG. 6A is a lateral view of the wiper for avoiding ink residues adhering on side surfaces of the print head according to the second embodiment of the invention; 
     FIG. 6B is a perspective view of the wiper for avoiding ink residues adhering on side surfaces of the print head according to the second embodiment of the invention; 
     FIG. 6C is a lateral view of the wiper for avoiding ink residues adhering on side surfaces of the print head according to the second embodiment of the invention; 
     FIG. 6D is a lateral view of the wiping portion of FIG. 6C; 
     FIGS.  7 A˜ 7 F schematically illustrates the wiping sequences of the wiper of FIG. 6C for wiping the ink residues; 
     FIG. 8A shows a wiper of FIG. 6C with two wiping ends; and 
     FIG. 8B is a lateral view of the wiping portion of FIG.  8 A. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The wiper according to the invention comprises a main body and a base. Different from the conventional wiper, the wiper in this invention has a contacting end on the top of the wiping end. Both the contacting end and the wiping end are disposed in the main body of the wiper. The wiping end does not touch two side surfaces of the print head during the cleaning. Besides, the contacting end does not touch the nozzle surface while wiping the ink residues on the nozzle surface. Therefore, the main body is used for wiping the ink residues on the nozzle surface. It prevents the ink residues on the wiping end of the wiper from being shifted to side surfaces of the print head. It also prevents the ink residues adhering to the side surfaces of the print head from falling onto the paper. It keeps side surfaces of the print head clean and ensures the printing quality. 
     Referring to FIGS. 3A,  3 B, and  3 C, it respectively show the exploded view, the perspective view, and the lateral view of the wiper for avoiding ink residues adhering on side surfaces of the print head according to the first embodiment of the invention. As shown in FIG. 3A, the wiper  300  is used for wiping the ink residue  111  on the print head  102  of FIG.  1 B and comprises a main body  302  and a base  314 . The main body  302  comprises a supporting portion  304 , flexible portion  306 , and wiping portion  308 . The supporting portion  304  has a protruding end  304   a  and a positioning hole  305  while the base  314  has a groove  314   a  and a positioning bolt  307  disposed in the inner wall of the groove  314   a . With a combination of the main body  302  and the base  314  along the direction of the arrow sign  350  of FIG. 3A, the protruding end  304   a  is inserted and wedged into the groove  314   a , the positioning hole  305  receives the positing bolt  307 , and therefore the main body  302  is mounted on the base  314 . 
     Referring to FIG. 3C, the flexible portion  306  is disposed upon the supporting portion  304  while the wiping portion  308  is disposed upon the flexible portion  306 . The supporting portion  304 , flexible portion  306 , and wiping portion  308  are in one unity. Referring to FIG. 3D, it shows a view of the wiping portion of FIG.  3 C. The wiping portion  308  includes a contacting end  310  and wiping ends  312   a  and  312   b . The wiping ends  312   a  and  312   b  extend from the left and right sides of the wiping portion  308  respectively while the contacting end is positioned on the top of the wiping portion  308 . As shown in FIG. 3D, the wiping portion  308  is inverted triangle-shaped while the wiping ends  312   a  and  312   b  are disposed at opposing sides of the wiping portion  308  and form two acute angles on the base side of the inverted triangle. The contacting end  310  is not level with wiping ends  312   a  and  312   b . When the flexible portion  306  bends down, the vertex of the wiping ends  312   a  or  312   b  might be higher than the vertex of the contacting end  310 . 
     The wiping sequences of the wiper of FIG. 3C for wiping the ink residues are schematically illustrates in FIGS.  4 A˜ 4 F. Referring first to FIG. 4A, when the wiping ends  312   a  and  312   b  do not touch the nozzle surface  110 , the contacting end  310  is higher than the plane level L of the nozzle surface  110  and the wiping ends  312   a  and  312   b  are lower than the plane level L of the nozzle surface  110 . 
     As shown in FIG. 4A, when the print head  102  approaches the contacting end  310  along the direction of the arrow sign  360  and the side surface  102   a  touches the contacting end  310 , the side surface  102   a  of the print head  102  pushes the contacting end  310  so that the flexible portion  306  bends to the right and the wiping end  312   a  touches the nozzle surface  110  as shown in FIG.  4 B. Before the contacting end  310  touches the print head  102 , the wiping end  312   a  is lower than the nozzle surface  110 ; thus the side surface  102   a  is unable to touch the wiping end  312   a . When the wiping end  312   a  touches the nozzle surface  110  and removes the ink residue  111  on the nozzle surface  110 , the flexible portion  306  bends down and the wiping end  312   a  touches the nozzle surface  110 ; thus the contacting end  310  is unable to touch the nozzle surface  110 . 
     When the wiping end  312   a  comes off the nozzle surface  110 , the ink residue  111  successfully adheres to the left side of the wiping end  312   a  as shown in FIG.  4 C. Meanwhile, the flexible portion  306  recovers to the former shape. Referring to FIG. 4C, as the print head  102  approaches the contacting end  310  along the direction of the arrow sign  370  of FIG. 4C, the side surface  102   b  of the print head  102  touches the contacting end  310  and the print head  102  proceeds to move along the direction of the arrow sign  370 . When the side surface  102   b  of the print head  102  pushes the contacting end  310 , the flexible portion  306  bends to the left and the wiping end  312   b  touches the nozzle surface  110  as shown in FIG.  4 D. Before the contacting end  310  touches the print head  102 , the wiping end  312   b  is lower than the nozzle surface  110 ; thus the side surface  102   b  is unable to touch the wiping end  312   b . When the wiping end  312   b  touches the nozzle surface  110  and removes the ink residue  111  on the nozzle surface  110 , the flexible portion  306  bends down and the wiping end  312   b  touches the nozzle surface  110 ; thus the contacting end  310  is unable to touch the nozzle surface  110 . 
     Referring to FIG. 4E, the wiping end  312   b  comes off the nozzle surface  1110  and the flexible portion  306  recovers to the former shape. The ink residue  111  remains adhering to the left side of the wiping end  312   a . After that, when the print head  102  approaches the contacting end  310  and the side surface  102   a  of the print head  102  touches the contacting end  310  again, the ink residue  111  adhering to the left side of the wiping end  312   a  will not be shifted to the side surface  102   a  of the print head  102  since the side surface  102   a  is unable to touch the wiping end  312   a . Subsequently, the print head  102  proceeds to move along the arrow sign  360  of FIG.  4 F. The wiping end  312   a  will bend and then touch the nozzle surface  110  to perform wiping. Once the wiping end  312   b  comes off the nozzle surface  110 , the ink residue  111  remains adhering to the left side of the wiping end  312   a  and the flexible portion  306  recovers to the former shape. 
     In the first embodiment, the wiper  300  according to the invention not only cleans the ink residue  111  on the nozzle surface  100  but also prevents the ink residue  111  from being shifted to side surface  102   a  or  102   b  of the print head  102 . It avoids the ink residue  111  falling on the paper to be print  104  when the print head is quickly printing back and forth. This keeps the side surfaces of the print head clean and ensures the printing quality. 
     The wiping ends  312   a  and  312   b  in the first embodiment are respectively disposed at the opposing sides of the wiping portion  308  and form two acute angles. Furthermore, wiping end can also comprise a plurality of protrusions since the wiping effect can become even better by increasing the number of the wiping ends. Referring to FIG. 5A, it shows a wiper of FIG. 3C added with two wiping ends. The wiping portion  508  has wiping ends  312   a  and  512   a  on the left side and wiping ends  312   b  and  512   b  on the right side. The wiping sequences are similar and thus the wiping details are omitted. 
     Referring to FIGS. 6A,  6 B, and  6 C, they respectively show the exploded view, perspective view, and lateral view of the wiper for avoiding ink residues on side surfaces of the print head according to the second embodiment of the invention. As shown in FIG. 6A, the wiper  600  is used for wiping the ink residue  111  on the print head  102  and comprises a main body  602  and a base  314 . The main body  602  comprises a supporting portion  304 , flexible portion  306 , and wiping portion  608 . The supporting portion  304  has a protruding end  304   a  and a positioning hole  305  while the base  314  has a groove  314   a  and a positioning bolt  307  is disposed in the inner wall of the groove  314   a . With a combination of the main body  602  and the base  314  along the direction of the arrow sign  650  of FIG. 6A, the protruding end  304   a  is inserted and wedged into the groove  314   a , the positioning hole  305  receives the positing bolt  307 , and therefore the main body  602  is mounted on the base  314  as shown in FIGS. 6B and 6C. 
     Referring to FIG. 6C, the flexible portion  306  is disposed upon the supporting portion  304  while the wiping portion  608  is disposed upon the flexible portion  306 . The supporting portion  304 , flexible portion  306 , and wiping portion  308  are in one unity. Referring to FIG. 6D, it shows an enlarged view of the wiping portion of FIG.  6 C. The wiping portion  608  includes a contacting end  610  and wiping ends  612   a  and  612   b . The wiping ends  612   a  and  612   b  extend from left side and right side of the wiping portion  608  while the contacting end  610  is positioned on the top of the wiping portion  608 . As shown in FIG. 6D, the wiping portion  608  is trapezoid-shaded. The contacting end  610  is used for bending the flexible portion  306  and positioned on the top of the wiping portion  608 , in other words, on the upper parallel side of the trapezoid. The wiping ends  612   a  and  612   b  on opposing sides of the wiping portion  308  are disposed on the lower parallel side of the trapezoid and form two acute angles of the lower parallel side of the trapezoid. The contacting end  610  is not level with wiping ends  612   a  and  612   b . When the flexible portion  306  bends down, the vertex of the wiping end  612   a  or  612   b  might be higher than the top of the contacting end  610 . 
     The wiping sequences of the wiper of FIG. 6C for wiping the ink residues are schematically illustrated in FIGS.  7 A˜ 7 F. Referring first to FIG. 7A, when the wiping ends  612   a  and  612   b  do not touch the nozzle surface  110 , the contacting end  610  is higher than the plane level L of the nozzle surface  110  and the wiping ends  612   a  and  612   b  are lower than the plane level L of the nozzle surface  110 . 
     As shown in FIG. 7A, the print head  102  approaches the contacting end  610  along the direction of the arrow sign  660  of FIG.  7 A. When the side surface  102   a  of the print head  102  touches the contacting end  610  and the print head  102  proceeds to move along the direction of the arrow sign  660 , the side surface  102   a  of the print head  102  pushes the contacting end  610  so that the flexible portion  306  bends to the right and the wiping end  612   a  touches the nozzle surface  110  as shown in FIG.  7 B. Before the contacting end  610  touches the print head  102 , the wiping end  612   a  is lower than the nozzle surface  110 ; thus the side surface  102   a  is unable to touch the wiping end  612   a . When the wiping end  612   a  touches the nozzle surface  110  and removes the ink residue  111  on the nozzle surface  110 , the flexible portion  306  bends down and the contacting end  610  is lower than the nozzle surface  110 ; thus the contacting end  610  is unable to touch the nozzle surface  110 . 
     When the wiping end  612   a  comes off the nozzle surface  110 , the ink residue  111  has successfully adhered to the left side of the wiping end  612   a  as shown in FIG.  7 C. Meanwhile, the flexible portion  306  recovers to the former shape. Referring to FIG. 7C, the print head  102  approaches the contacting end  610  along the direction of the arrow sign  670 . When the side surface  102   b  of the print head  102  touches the contacting end  610  and the print head  102  proceeds to move along the direction of the arrow sign  670 , the side surface  102   b  of the print head  102  subsequently pushes the contacting end  610  so that the flexible portion  306  bends to the left and the wiping end  612   a  touches the nozzle surface  110  as shown in FIG.  7 D. Before the contacting end  610  touches the print head  102 , the wiping end  612   b  is lower than the nozzle surface  110 ; thus the side surface  102   b  is unable to touch the wiping end  612   b . When the wiping end  612   b  touches the nozzle surface  110  and removes the ink residue  111  on the nozzle surface  110 , the flexible portion  306  bends down and the contacting end  610  is lower than the nozzle surface  110 ; thus the contacting end  610  is unable to touch the nozzle surface  110 . 
     Referring to FIG. 7E, the wiping end  612   b  comes off the nozzle surface  110  and the flexible portion  306  recovers to the former shape. The ink residue  111  remains adhering to the left side of the wiping end  612   a . When the print head  102  approaches the contacting end  610  and the side surface  102   b  of the print head  102  touches the contacting end  610  again, the ink residue  111  adhering to the left side of the wiping end  612   a  will not be shifted to the side surface  102   a  of the print head  102  since the side surface  102   a  is unable to touch the wiping end  612   a . Subsequently, the print head  102  proceeds to move along the arrow sign  660  of FIG.  7 F. The wiping end  612   a  touches the nozzle surfaces  110  and performs wiping. Once the wiping end  612   b  comes off the nozzle surface  110 , the ink residue  111  remains adhering to the left side of the wiping end  612   a  and the flexible portion  306  recovers to the former shape. 
     In the second embodiment, the wiper  600  according to the invention not only cleans the ink residue  111  on the nozzle surface  110  but also prevents the ink residue  111  from being shifted to side surface  102   a  or  102   b  of the print head  102 . It avoids the ink residue  111  falling on the paper to be print  104  when the print head is quickly printing back and forth. This keeps the side surfaces of the print head clean and ensures the printing quality. 
     The wiping ends  612   a  and  612   b  in the second embodiment are respectively disposed at the opposing sides of the wiping portion  608  and form two acute angles. Furthermore, wiping end can also comprise a plurality of protrusions since the wiping effect can become even better by increasing the number of the wiping ends. Referring to FIG. 8A, showing a wiper of FIG. 6C added with two wiping ends. The wiping portion  808  has wiping ends  612   a  and  812   a  on the left side and wiping ends  612   b  and  812   b  on the right side. The wiping sequences are similar and the wiping details are omitted. 
     The wiping portion according to the invention at least comprises a contacting end and a wiping end on the condition that the contacting end is positioned on the top of the wiping portion while the wiping end extends from one side of the wiping portion. Before wiping, the contacting end is higher than the nozzle surface and the wiping end is lower than the nozzle surface. During wiping, the contacting end is unable to touch the nozzle surface and the wiping end is unable to touch the side surface of the print head. It prevents the ink residues on the main body from being shifted to the side surfaces of the print head. Besides, the wiper with more wiping ends can increase the wiping effect. 
     The wiper according to the aforementioned embodiments avoids ink residues from being shifted to the side surfaces of the print head again by the special design of the contacting end and the wiping end. It keeps side surfaces of the print head clean and prevents the contamination of ink residues to ensure the printing quality. 
     While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.