Patent Publication Number: US-2007103504-A1

Title: Maintenance Device for Cleaning Ink Cartridge Print Heads

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a maintenance device capable of cleaning a print head of an ink cartridge, and more particularly, to a maintenance device capable of capping a print head of an ink cartridge, removing ink residue from the print head, pumping ink from the print head of the ink cartridge, and scraping off the ink residue from a wiper without requiring an external driving force to achieve the above functions.  
      2. Description of the Prior Art  
      Modern office equipment utilized for document processing includes: printers, fax machines, photocopiers, and many other similar devices. To meet the high quality standards that are expected of printing devices, the most commonly used being the ink jet printer; most machines will require an external maintenance device. Most ink jet printers also require an external maintenance device for cleaning and maintaining the print head. The external maintenance device helps to prevent ink smudges and ensure that each printed sheet is error-free.  
      The primary components of the external maintenance devices currently on the markets are: a wiper, a cap, a scraper, and a pump. The primary function of the wiper is to remove the ink residue from the print head. The function of the cap is to cover the print head when the print head returns to an original point. The print head cover is to prevent the ink residue from drying, which can cause congestion in a nozzle. The function of the scraper is to scrape the ink residue off the wiper. Finally, the primary function of the pump is to pump ink to the dry print head before a printing job. This is necessary to ensure the quality of the output document will not affected by a dry nozzle.  
      In the case when the maintenance device in the modern office equipment supports all four functions as described above, the office equipment will require a third motor in addition to a first motor, used for feeding paper, and a second motor, used for moving a carriage that carries the ink cartridge back and forth. The third motor is necessary for supporting the operation of the four maintenance functions. For example, U.S. Pat. No. 5,997,128 discloses a technology that utilizes the third motor for driving the wiper and the cap, if the third motor is not utilized; the number of driving component is increased to drive the sled carrying the wiper and the cap back and forth within the printer. Additionally, in this architecture, if an increase in the pump function is required a resulting possibility is a separation of the pump tube due to the back and forth action of the cap. U.S. Pat. No. 6,520,620 discloses a technology that utilizes the third motor to achieve the functions of removing the ink residue, capping the print head, and pumping ink, but the technology still cannot remove the ink residue on the print head during the printing operation. U.S. Pat. No. 6,742,863 discloses that the force of the non-ink cartridge carrier is required to drive (i.e., force of the motor) the wiper architecture, but the technology still cannot remove the ink residue on the print head. U.S. Pat. No. 6,168,257 discloses a technology that utilizes the back and forth action of the ink cartridge carriage to drive the cap and the wiper, the wiper utilizes the method of moving diagonally upwards and in between the two corners of the carriage, but the function of the scraper cannot be integrated with this architecture, thus the ink residue on the wiper may cause an ink smudge problem. Additionally, with regard to the action of the carriage driving the cap, the capping force and the size of the motor must be appropriate otherwise, the capping function will fail, furthermore, the failed capping function will cause the pumping function to fail. Additionally, this design can cause an increase in the width of the maintenance device, which is undesirable given the current trend towards miniature design.  
     SUMMARY OF THE INVENTION  
      The claimed invention provides a maintenance device capable of capping a print head of an ink cartridge, cleaning ink residue from the print head, pumping ink from the print head of the ink cartridge, and scraping the ink residue off a wiper without requiring an external driving force to perform the above-mentioned operations.  
      The claimed invention discloses a maintenance device capable of cleaning a print head of an ink cartridge, the maintenance device comprises a maintenance module comprising a base, a cap for capping a print head of an ink cartridge, a cap sled installed on the base in a sliding manner for driving the cap upwards to cover the print head of the ink cartridge, an end of the cap sled having a rack. The maintenance device further comprises a pump module for pumping ink out of the print head of the ink cartridge, the pump module comprises a pump gear for engaging a feed gear, a swing gear for engaging the pump gear, and a swing arm coupled to the pump gear and the swing gear for driving the swing gear when being driven by the pump gear when the feed gear is driving the pump gear; wherein the swing gear and the rack of the cap sled are installed at a location corresponding to where the swing gear engages the rack of the cap sled when the swing arm moves the swing gear to a predetermined position.  
      These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  illustrates an external view of a maintenance device according to the present invention.  
       FIG. 2  illustrates an external view of a maintenance device according to the present invention.  
       FIG. 3  illustrates an external view of a pump module.  
       FIG. 4  illustrates a diagram of a maintenance device in an initialization status.  
       FIG. 5  illustrates a diagram of a maintenance device in an operational status.  
       FIG. 6  illustrates a diagram of a swing gear driving a cap sled in a +X direction.  
       FIG. 7  illustrates a diagram of a bar resisting rotation of a swing bar.  
       FIG. 8  illustrates a diagram of a swing gear driving a cap sled in a −X direction.  
       FIG. 9  illustrates a diagram of a carriage carrying two ink cartridges at different locations when a wiper sled is in an operational status of raising the wiper.  
       FIG. 10  illustrates a diagram of a carriage carrying two ink cartridges at different locations when a wiper sled is in an operational status of raising the wiper.  
    
    
     DETAILED DESCRIPTION  
      Please refer to  FIG. 1 .  FIG. 1  illustrates an external view of a maintenance device  10  according to the present invention. The maintenance device  10  includes a maintenance device  12 , and a pump device  14 . Please refer to  FIG. 2  and  FIG. 3 .  FIG. 2  illustrates an external view of a maintenance device  12  according to the present invention.  FIG. 3  illustrates an external view of a pump module  14 . As shown in  FIG. 2 , the maintenance device  12  includes a base  16 , two caps  18  for capping a print head of two ink cartridges, in this embodiment the maintenance device  12  is utilized for maintaining the print system of the twin ink cartridge, if the maintenance device  12  is utilized for maintaining a print system having a different number of ink cartridges, then a corresponding number of caps will be installed, a cap sled  20  installed on the base that moves in a sliding manner, the cap sled  20  is utilized for the maintenance of driving the cap upwards to cover the print head of the ink cartridge, an end of the cap sled  20  includes a rack  22 , two wipers  24 , a wiper sled  26  for pushing a carriage of the ink cartridge being carried upwards to drive the wiper  24 , and a lock bar  28  connected to the wiper sled  26  for wedging a stop component  30  of the base  16  to secure the wiper sled  26 , wherein the stop component  30  is a convex block, an end of the lock bar  28  is a hook structure for wedging the convex block. The maintenance device  12  further comprises two scrapers  32 , installed on the cap sled  20 , for scraping ink residue off each wiper  24  when the cap sled  20  and the wiper  24  generate a corresponding movement, and a cap sled support  34  for limiting the movement direction of the cap sled  20 . As shown in  FIG. 3 , the pump module  14  is utilized for pumping ink out of the print head of the ink cartridge, the pump module  14  includes a pump gear  36  engaged with a feed gear  36  (as shown in  FIG. 1 ) and a swing gear  40  engaged with the pump gear  36 , and a swing arm  42  connected to the pump gear  36  and the swing gear  40  for moving the swing gear  40  being driven by the pump gear  36  when the feed gear  38  drives the pump gear  36  so that the swing gear  40  can engaged the rack  22  of the cap sled  20 , thus the swing gear  40  and the rack  22  of the cap sled  20  are installed on corresponding positions where the swing gear  40  engages the rack  22  of the cap sled  20  when the swing arm  42  moves the swing gear  40  to a predetermined location. The driving force of the pump  14  comes from the feed gear  38 , a feed roller rotates to drive the feed gear  38 . As the feed gear  38  and the pump gear  36  engage each other, the feed gear  38  can drive the pump gear  36  to rotate and compress a tube of a support  44  to pump ink out of the ink cartridge capped by the cap  18 . Furthermore, a bar  46  is installed on the wiper sled  26  for resisting the rotation of the swing gear.  
      Please refer to  FIG. 4  and  FIG. 5 .  FIG. 4  illustrates a diagram of a maintenance device  12  in an initialization status.  FIG. 5  illustrates a diagram of a maintenance device  12  in an operational status. When a printer is in a printing status, the maintenance device  12  is in the initialization status as shown in  FIG. 4 , the cap sled  20  and the wiper sled  26  are also in the initialization status, thus the cap  18  and the wiper  24  are not raised yet; when the printer is in a capping and pumping ink status, the cap sled  20  and the wiper sled  26  are in an operational status, which drives the cap  18  and the wiper  24  to rise.  
      Please refer to  FIG. 6  for an explanation of the operational theory of the cap sled  20  being driven.  FIG. 6  illustrates a diagram of a swing gear  40  driving a cap sled  20  in a +X direction. When the wiper sled  26  is in the initialization status, if the printer is in a status of feeding paper, the feed gear  38  rotates in an counter-clockwise direction, and as the feed gear  38  engages the pump gear  36 , the feed gear  38  drives the pump gear  36  to rotate in a clockwise direction, the swing arm  42  coupled to the pump gear  36  at the same time is also being driven by the pump gear  36  to rotate with the axis of the pump gear  36  in the clockwise direction, therefore the swing gear  40  that is connected to the swing arm  42  also rotates with the axis of the pump gear  36  in the clockwise direction, and when the swing arm  42  rotates in the clockwise direction to engage with the swing gear  40  and the rack  22  of the cap sled  20 , as the swing gear  40  itself is already engaged with the pump gear  36 , thus the pump gear is being driven to rotate in the counter-clockwise direction, at this time the cap sled  20  is being driven in the +X direction as shown in  FIG. 2  and  FIG. 5 , and the cap  18  moves downwards along the slanting track of the cap sled  20  such that the cap  18  is not able to rise to the position needed for capping the print head of the ink cartridge.  
      Please refer to  FIG. 7 .  FIG. 7  illustrates a diagram of a bar  46  resisting rotation of a swing bar  40 . As shown in  FIG. 6  and  FIG. 7 , when the wiper sled  26  is in the initialization status, if the feed gear  38  is rotating in the clockwise direction to drive the pump gear to rotate in the counter-clockwise direction, at the same time the swing arm  42  that is connected to the pump gear  36  is being driven by the pump gear  36  to rotate with the axis of the pump gear in the counter-clockwise direction, therefore the swing gear  40  that is connected to the swing arm  42  also rotates in the counter-clockwise direction with the axis of the pump gear  36 . At this time the wiper sled  26  is in the initialization status, thus the bar installed on the wiper sled  26  resists the rotation of the swing gear  40 , and the cap sled  20  cannot be driven, hence the cap  18  cannot rise to the position needed for capping the print head of the ink cartridge.  
      Please refer to  FIG. 8 .  FIG. 8  illustrates a diagram of a swing gear  40  driving a cap sled  20  in a −X direction. When the carriage of the ink cartridge moves to the capping position to perform capping, the wiper sled  26  is in the operational status of raising the wiper  24 , if the feed gear  38  rotates in the clockwise direction, and as the feed gear  38  engages the pump gear  36 , the feed gear  38  drives the pump gear  36  to rotate in the counter-clockwise direction, the swing arm  42  that is connected to the pump gear  36  at the same time is also being driven by the pump gear  36  to rotate with the axis of the pump gear  36  in the counter-clockwise direction, therefore the swing gear  40  that is connected to the swing arm  42  also rotates with the axis of the pump gear  36  in the counter-clockwise direction. As the wiper sled  26  is in the operational status of raising the wiper  24 , thus the wiper sled  26  moves to a location where the bar  46  of the wiper  26  does not resist the rotation of the swing gear  40 , therefore the swing arm  42  can rotates in the counter-clockwise direction to engage with the swing gear  40  and the rack  22  of the cap sled  20 , as the swing gear  40  itself is already engaged with the pump gear  36 , thus the pump gear is being driven to rotate in the clockwise direction, at this time the cap sled  20  is being driven in the −X direction as shown in  FIG. 2  and  FIG. 5 , and the cap  18  moves upwards along the slanting track of the cap sled  20  such that the cap  18  rises to the position needed to cap the print head of the ink cartridge.  
      Please refer to  FIG. 9  and  FIG. 10 .  FIG. 9  and  FIG. 10  illustrate a diagram of a carriage  50  carrying two ink cartridges  48  at different locations when a wiper sled  26  is in an operational status of raising the wiper  24 . When the carriage  50  moves towards the left end to bring the two ink cartridges  48  back to the original location, the carriage  50  drives the wiper sled  26  to move towards the left, therefore the wiper  24  moves upwards on a track  51 , and at this time the lock bar  28  connected to the wiper sled  26  is wedged within the stop component  30  of the base  16  to secure the wiper sled  26 . As shown in  FIG. 9  and  FIG. 10 , the wiper  24  is being driven upwards to a location higher than a print head  52  of the two ink cartridges  48 , when the carriage  50  moves towards the right end from a location shown in  FIG. 9  to a location shown in  FIG. 10  to drive the two ink cartridges  48  towards the right, as interference is generated on the surface of the wiper  24  and the print head  52  of the ink cartridges  48 , the wiper  24  can perform the action of removing ink residue. The lock bar  28  and the stop component  30  are interlocked to provide a lock force during the execution of removing ink residue, as the wiper sled  26  and the wiper  24  will not be driven due to the interference generated by the ink cartridge  48  and the wiper  24 . After the ink residue is removed by the wiper  24 , the carriage  50  continues to move to the right, at this time the carriage  50  pushes the top end of the lock bar  28  so that the lock bar  28  corresponding to the locked area with the stop component rotates, in doing so the bottom end of the lock bar  28  separates from the stop component  30 , thus the wiper sled  26  can return to its original initialization status, which means that the wiper  24  will move down to a location lower than the print head  52  of the two ink cartridges  48 . The wiper  24  of the present invention performs a method of up and down vertical movement. The present invention does not utilize the conventional method of the wiper  24  moving upwards in a diagonal manner to locate itself between the two ends of the carriage. As a result, the present invention is capable of reducing the width of the maintenance device.  
      In conclusion, when the printer is in the printing status, the wiper sled  26  and the cap sled  20  are in the initialization status, which means that the wiper  24  and the cap  18  are not yet raised; when the printer is in the capping and pumping status, the wiper sled  26  is being driven towards the left by the carriage  50 , the wiper  24  will be driven upwards within the track  51 , thus the wiper sled  26  is in the operational status of rising the wiper  24 , in another words, the bar  46  installed on the wiper sled  26  will not resist the swing gear from rotating, at this time the feed gear  38  rotates in the clockwise direction, thus the swing gear  40  also rotates in the clockwise direction. The cap sled  20  is then being driven in the −X direction as shown in  FIG. 2  by the swing gear  40 , and the cap  18  moves upwards along the slanting track of the cap sled  20  to the location needed for capping the print head  52 , thus the capping and pumping operation is executed on the print head  52 ; and when the printer is wiping the ink residue, as the lock bar  28  is wedged with the stop component  30  of the base  16 , the wiper sled  26  is being locked in the operational status of raising the wiper  24 , and the print head  52  of the ink cartridge  48  after wiping performs the printing operation, the feed gear  38  will rotate in the counter-clockwise direction, at this time the cap sled  20  is being driven in the +X direction as shown in  FIG. 2  by the swing gear  40 , and the cap  18  moves downwards along the slanting track of the cap sled  20 , and the cap  18  will not be positioned in the location of capping the print head of the ink cartridge; after the wiper  24  execute the wiping operation on the print head  52 , the carriage  50  continues to move right, at this time the carriage  50  pushes the top end of the lock bar  28  so that the lock bar  28  corresponding to the locked area with the stop component rotates, in doing so the bottom end of the lock bar  28  separates with the stop component  30 , thus the wiper sled  26  and the cap sled  20  can return to their original initialization status. Furthermore, in the back and forth movement of the cap sled  20 , as the cap sled  20  and the wiper  24  generate a relative motion, the sled  32  is capable of wiping the ink residue off the wiper  24 .  
      In comparison to the conventional maintenance device, the maintenance device of the present invention requires the motor for feeding paper and the motor for moving the carriage for driving the ink cartridge to act as a driving force without requiring an external driving force, the present invention also solves the limitation of not being able to remove the ink residue during printing, and finally the present invention does not increase the width of the maintenance device such that the present invention achieves the four functions such as capping the print head, wiping ink residue from the print head, pumping ink from the print head of the ink cartridge, and scraping the ink residue off the wiper, in doing so, the cost of the maintenance device can be reduced and it is in step with the current trend of miniature design.  
      Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.