Patent Publication Number: US-2004041888-A1

Title: Ink cartridge

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001] This application claims the benefit of Korean Patent Application No. 2002-51605, filed Aug. 29, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002] 1. Field of the Invention  
       [0003] The present invention relates to an ink cartridge, and particularly, to an ink cartridge preventing air from flowing into a printing head chip during printing using ink.  
       [0004] 2. Description of the Related Art  
       [0005] Generally, an ink cartridge for an inkjet printer includes a main body filled with ink, and the ink in the main body is sprayed onto a paper by a predetermined amount at a time through an ink head chip provided to the main body.  
       [0006]FIG. 1 is a view showing an ink cartridge  1  disclosed in U.S. Pat. No. 5,742,311. Referring to FIG. 1, the ink cartridge  1  has a two-chamber structure to maintain a negative pressure. An inside of the ink cartridge  1  is divided into a foam chamber  4  receiving a foam  3 , such as a sponge, and an ink chamber  6  filled with ink  1 . The ink and foam chambers  3  and  4  are divided by a partition  5  to left and right sections. Between a lower end of the partition  5  and a bottom  1  a inside the ink cartridge  1 , a passage  9  is provided to pass ink and air.  
       [0007] At one side of the partition  5  forming a side of the foam chamber  4 , a long slot  5   a  is formed to feed air. The foam chamber  4  is provided at an upper portion with an air vent  1   b . A lower portion of the foam chamber  4  is connected with a pipe  7  used as ink passage feeding the ink L to a printing head (not shown). At an orifice of the pipe  7  coupled to another side of the ink chamber  4 , a filter  8  is disposed.  
       [0008] According to the above construction of the ink cartridge  1 , the filter  8  is disposed higher than the passage  9  with respect to the bottom  1   a  of the ink cartridge  1 . This may cause air to flow through an air passage inside the foam  3  to the printing head upon use of the ink cartridge  1 . To prevent this, the long slot  5   a  is formed on the partition  5 . When a surface of the ink L is disposed above the long slot  5   a , the air enters the ink chamber  6  through the long slot  5   a  and the passage  9  so that the ink I in the ink chamber  6  can be used stably.  
       [0009] However, with the conventional ink cartridge of the above construction, the number of operations of a metallic mold process of the ink cartridge  1  is increased, thus a mold processing cost is increased, causing troubles in a mass production. Further, in a case that the long slot  5   a  gets clogged, and the air moves through the pipe  7  to the head chip, so that normal printings are not possible.  
       SUMMARY OF THE INVENTION  
       [0010] An aspect of the invention is to solve the above and/or other problems and to provide an improved ink cartridge having a simple construction capable of blocking air from flowing into a head chip.  
       [0011] Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.  
       [0012] Accordingly, an aspect of the present invention is to solve the foregoing and/or other problems by providing an ink cartridge including a main body divided into an ink chamber filled with ink and a foam chamber receiving an ink absorbent body, an ink head chip disposed at a lower portion of the foam chamber to spray the ink onto a printing paper, a partition forming a passage with a bottom of the main body to pass ink and air therethrough, and dividing the ink chamber and the foam chamber, and an ink feeding pipe disposed lower than the passage and at the lower portion of the foam chamber to feed the ink in the foam chamber to the ink head chip.  
       [0013] Here, the ink feeding pipe is provided at a side of the foam chamber with an ink filter filtering the ink.  
       [0014] According to another aspect of the invention, the ink feeding pipe is disposed in a vertically upright position such that an upper end thereof is lower than the passage.  
       [0015] Moreover, the main body is provided with a protruding rib, at which the ink head chip is disposed outside the form chamber, protruding from a bottom of the foam chamber to a lower direction to receive the ink feeding pipe. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0016] These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the preferred embodiment, taken in conjunction with the accompanying drawings of which:  
     [0017]FIG. 1 is a schematic cross-sectional view showing a conventional ink cartridge;  
     [0018]FIG. 2 is a schematic cross-sectional view showing an ink cartridge in accordance with an embodiment of the invention; and  
     [0019]FIG. 3 is a cross-sectional view illustrating a status of using the ink cartridge shown in FIG. 2. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0020] Reference will now be made in detail to the present preferred embodiment of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiment is described in order to explain the present invention by referring to the figures.  
     [0021] An ink cartridge according to an embodiment of the invention will be hereinafter described in detail with reference to the accompanying drawings.  
     [0022] Referring to FIG. 2, the ink cartridge includes a main body  20  having an inside divided into an ink chamber  21  and a foam chamber  23 , a head chip  30  disposed at a lower portion of the foam chamber  23 , a partition  40  disposed inside the main body  20  to divide the ink chamber  21  and the foam chamber  23 , an ink feeding pipe  50  feeding ink contained in the foam chamber  23  to the head chip  30 , and a filter  60  disposed at an upper end of the ink feeding pipe  50 .  
     [0023] Each of the ink chamber  21  and the foam chamber  23  is filled with the ink. The foam chamber  23  receives foam  40  such as a sponge. The foam chamber  23  is provided at an upper portion thereof with an air vent  23   a  through which air flows into the foam chamber  23 .  
     [0024] The partition  40  is disposed inside the main body  20  of the ink cartridge in a vertically upright position. The main body  20  is provided with a passage  22  disposed between a bottom  20   a  thereof and the partition  40 . Through the passage  22 , ink and air may be fed between the ink and foam chambers  21  and  23 .  
     [0025] The main body  20  has a protruding rib  25  protruding from a portion of the bottom  20   a  of the foam chamber  23  to a lower direction thereof. At an inside of the protruding rib  25 , the ink feeding pipe  50  is disposed, and at an outside thereof, the head chip  30  is disposed. The protruding rib  25  may be formed as a single body with the main body  20 .  
     [0026] The head chip  30  sprays the ink fed through the ink feeding pipe  50  onto a printing paper P based on a predetermined input data for printing. To this end, the head chip  30  includes a spray nozzle and a printing circuit controlling drive of the spray nozzle to perform printing by spraying a predetermined amount of the ink at a time according to the input data for printing.  
     [0027] The ink feeding pipe  50  is disposed in the protruding rib  25  communicating with an inside of the foam chamber  23  in a vertically upright position. The ink feeding pipe  50  is disposed such that an upper end thereof is lower than the passage  22 . The upper end of the ink feeding pipe  50  being lower than the passage  22  enables a surface A of the ink disposed inside the foam chamber  23  to reach the passage  22  first. Thus, as the air flows through the passage  22  from the foam chamber  23  to the ink chamber  21 , the ink in the ink chamber  21  may flow smoothly to the foam chamber  23 . Since the ink feeding pipe  50  is lower than the passage  22 , the air can be basically blocked from flowing into the ink feeding pipe  50  first.  
     [0028] The ink feeding pipe  50  is supported by a supporting member  27  disposed inside the protruding rib  25  to maintain the upright position. The supporting member  27  may be formed as a single body with the protruding rib  25 .  
     [0029] The ink feeding pipe  50  is provided at the upper end thereof with the filter  60 . Since the filter  60  is disposed at the upper end of the ink feeding pipe  50  and lower than the passage  22 , the filter  60  filters impurities from the ink flowing from the foam chamber  23  into the ink feeding pipe  60  to prevent the spray nozzle of the head chip  30  from being clogged, or polluted ink from being sprayed through the spray nozzle of the head chip  30 .  
     [0030] An operation of the ink cartridge according to the embodiment of the invention will be described hereinbelow.  
     [0031] As shown in FIG. 2, a printing operation is performed using a printer adopting the ink cartridge having the main body  20  with the ink chamber  21  and the foam chamber  23  filled with the ink. For the printing operation, the ink in the foam chamber  23  is used first. Thus, an ink level of the ink disposed only inside the foam chamber  23  is gradually lowered.  
     [0032] Thereafter, as shown in FIG. 3, the ink level inside the foam chamber  23  may be lowered more than the passage  22 . When this happens, as the air flows through the passage  22  from the foam chamber  23  into the ink chamber  21 , the ink in the ink chamber  21  flows into the foam chamber  23 . Therefore, the ink flowing into the foam chamber  23  is fed to the head chip  30  through the ink filter  60  and the ink feeding pipe  50 .  
     [0033] That is, the ink in the foam chamber  23  is used first, and then, the ink in the ink chamber  21  is used as the surface of the ink is lower than the passage  22 , such as a lower side of the partition  40  forming the passage  22  with the bottom  21  a. After all of the ink in the ink chamber  21  flows into the foam chamber  23 , the ink remaining in a lower portion of the foam chamber  23  is finally used.  
     [0034] As described above, since the filter  60  and the ink feeding pipe  50  are disposed lower than the passage  22 , the air inside the foam chamber  23  may be replaced by the ink in the ink chamber  21  before the air flows into the ink feeding pipe  50  even if the ink level inside the foam chamber  23  is lowered.  
     [0035] Therefore, the air flowing into the ink feeding pipe  50  is basically prevented until all of the ink inside the main body  20  is used up.  
     [0036] With the ink cartridge according to the invention, the filter and the ink feeding pipe are disposed lower than the passage between the foam chamber and ink chamber, whereby the air does not flow into the ink feeding pipe but flows smoothly into the ink chamber as the ink level inside the foam chamber is lowered.  
     [0037] Therefore, an additional configuration or construction is not necessary for an air inflow to the ink chamber, thus reducing a number of operations of a manufacturing process to reduce a manufacturing cost.  
     [0038] While the invention has been shown and described with reference to certain preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.  
     [0039] The foregoing embodiment and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.