Patent Publication Number: US-7219984-B2

Title: Consumed ink cartridge refilling process

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a process and system for refilling printer ink cartridges. 
   2. Background Art 
   Inkjet printers have gained popularity among computer users in view of their low initial cost and versatility. They also produce letter and graphic prints with high quality. The ink required by printing is provided by ink cartridges mounted to the print head of the printer. Ink is held in a carrier material such as foam fiber located within a cartridge, which is saturated with the ink. The printer extracts the ink from the cartridge by vacuum pressure and delivers it to the print head. Inkjet printers consume printing ink at a fast rate particularly when printing graphics and photographic pictures. As an ink cartridge only holds a limited amount of ink, the cartridges would require replacing frequently. Therefore, the cost of operating an inkjet printer is high with the necessity of having to replace the ink cartridges frequently. Furthermore, the spent cartridges are discarded in the garbage which contributes to the contamination of the natural environment. In order to alleviate the above problems, the users of inkjet printers seek to refill the consumed cartridges rather than replacing them with new cartridges so as to reduce the operating cost as well as the unnecessary discarding of the used cartridges. However, when the printer can no longer extract ink from an ink cartridge, there is actually still a trace of ink remaining within the cartridge. Such small amount of ink remnant would quickly become dry up to blockage at the cartridge nozzle and hardening of the carrier material particularly adjacent to the nozzle. When fresh ink is injected into the cartridge for refilling it under such condition, the harden carrier material would loose the required physical characteristic for holding the ink and delivering it to the print head under vacuum. Furthermore, the dry up remnant of ink at the nozzle also form blockage to impede the flow of ink out of the cartridge. 
   For the above reason, it has been problematic in the refilling of ink cartridges in that the nozzle of the cartridge without resolving the above problems. The blockage at the nozzle may be removed by cleaning the nozzle external surface with water if the cartridge is to be refilled as soon as the ink has been consumed. However, cleaning the nozzle externally often does not eliminate the blockage within the opening of the nozzle particularly when the cartridge has been removed from the printer for some time without refill it immediately. Also, it does not eliminate the hardening of the carrier material in the cartridge. Thus, the refilled cartridge either does not function or will only function inefficiently. Furthermore, the wiping operation would often destroy the physical structure of the nozzle. 
   Attempts have been made to remove the internal ink remnant from the cartridge by injecting hot water into the cartridge through the nozzle. However, since the openings of the nozzle of the cartridge are very small, such process is rather messy and unsatisfactory as very little amount of hot water would penetrate into the cartridge. 
   SUMMARY OF THE INVENTION 
   It is a principal object of the present invention to provide a process of refilling an inkjet printer cartridge such that it is clog-free and will function as efficiently as a new cartridge. 
   It is another object of the present invention to provide a process of removing clogging ink remnant completely from a consumed ink cartridge. 
   It is another object of the present invention to provide a process of cleaning the ink carrying medium within a consumed ink cartridge to revive its ink retaining characteristic. 
   It is yet another object of the present invention to provide a system of refilling an ink cartridge having a high ink delivery characteristic. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments thereof in connection with the accompanying drawings in which 
       FIG. 1  is an enlarged front and bottom perspective elevation view of an inkjet cartridge with a portion of the enclosure removed to show the ink carrying medium located therein. 
       FIG. 2  is a perspective side elevation view of the system for cleaning the cartridge for remnant ink therein prior to refilling with ink according to the present invention with the steam guard tube shown in partial cross section. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   With reference to the drawings, an inkjet cartridge  10  has a casing  11  having a nozzle  12 . Ink holding medium  13  such as foam fiber or similar material is commonly located within the casing  11 . The medium  13  is saturated with ink when the cartridge is filled and it ensures that ink will be delivered to the print head of the printer satisfactorily. A pattern of electrical contacts  14  is provided on the casing  11  for actuating the ink delivery control system when the cartridge is inserted into the printer. When the ink is depleted in the cartridge, it must be replaced or refilled. Although an ink cartridge can no longer deliver ink to the print head for the printing operation, some ink actually still remain in the cartridge. Such remnant ink often forms blockage of the cartridge nozzle as well as hardening of the carrier medium  13  in the portion adjacent to the cartridge nozzle particularly if the cartridge is not refilled immediately. The harden carrier medium will eventually loose its capability of holding ink even when the cartridge is refilled and ink will no longer be delivered to the print head satisfactorily. Thus, in refilling the cartridge, the nozzle and the ink retaining foam must be thoroughly cleaned in order that the refilled cartridge would operate satisfactorily. 
   According to the present invention, prior to refilling the consumed ink cartridge, it is first cleaned by injecting short bursts of steam with a steam pressure of from 5 to 45 psi with a temperature of about 100° C. through the nozzle  12 . The steam may be provided with a handheld steam gun  15  having a manually operable trigger  16 . The gun  15  is connected to a steam generator (not shown). This operation may be carried out quickly and easily with relatively small ink cartridges since the steam would breakdown any dry ink blockage formed at the nozzle and penetrate into the cartridge to clean the carrier medium so as to return it to its original physically characteristic of ink retention. A suction vacuum device similar to the gun  15  may then be applied at the nozzle to extract the cleaning steam water from the cartridge with a suction vacuum pressure of about 20 to 29 Hg. For relatively larger ink cartridges, in order to assure the penetration of the steam into the cartridge, a high temperature relatively soft silicone tube  17  is mounted over the steam nozzle  18  of the gun. The end of the soft silicone tube  17  is held in contact with the nozzle  12  of the cartridge  10  as best shown in  FIG. 2  to serve as a guard to confine the steam over the area of the nozzle  12  of the cartridge  10 . A hand operated steam gun  12  is shown as an example, it can be appreciated by those skilled in the art that the cartridge  10  may be mounted onto a steam generating device having silicone tube aligned in contact with the cartridge nozzle such that the steam may be injected into the cartridge by operating the steam generator. Steam under the desirable pressure will effectively be injected into the cartridge through the nozzle  12  to dissolve the remnant dry up ink from the nozzle as well as from the carrier medium. The entire operation may be carried out quickly without causing the dissolved ink and water from splashing over the cleaning station. The operation may be repeated until the ink remnant is completely eliminated from the cartridge. 
   Since the steam is applied to the cartridge in very short intervals, it would not cause deterioration of the ink carrier medium or the physical integrity of the nozzle structure since the nozzle is not touch physically in the entire operation. 
   Once the cartridge has been completely cleaned, it may then be refilled by temporarily blocking the nozzle  12  and then injecting the ink into the cartridge under pressure through a filling opening formed in a selected location of the casing  11 . Commonly, the filling is carried out with an opening formed at a location opposite to the nozzle  12  so as to ensure the entire ink carrier medium  13  is saturated with the ink in the filling operation. 
   While the present invention has been shown and described in the preferred embodiments thereof, it will be apparent that various modifications can be made therein without departing from the spirit or essential attributes thereof, and it is desired therefore that only such limitations be placed thereon as are imposed by the appended claims.