Abstract:
This invention relates to an ink jet device that is adaptive for preventing formation of a bad pattern as well as improving the life span of the ink jet device. An ink jet device according to an embodiment of the present invention includes: a maintaining/repairing stage filled with cleaning water; a plurality of nozzles to be submerged into the maintaining/repairing stage filled with the cleaning water; a plurality of chambers connected to the nozzles in a one-to-one relationship, wherein a volume of each chamber is variable by a pressing means; a supply tube that supplies a discharged material; a discharging tube that discharges a contaminant and the cleaning water from at least one of the nozzle and the chamber; a collecting and delivering part connected to the supply tube, the discharging tube and the chambers that supplies the discharged material from the supply tube to the chambers and supplying the contaminant and the cleaning water from the chambers to the discharging tube; and a pump connected to the discharging tube that pumps the contaminant and the cleaning water to the discharging tube.

Description:
[0001]     This application claims the benefit of Korean Patent Application No. P2005-0107630, filed on Nov. 10, 2005, which is hereby incorporated by reference for all purposes as if fully set forth herein.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to an ink jet device, and more particularly to an ink jet device that prevents the formation of bad ink patterns as well as improving the life span of the ink jet device.  
         [0004]     2. Description of the Related Art  
         [0005]     An ink jet device is a printing device that sprays ink through a plurality of nozzles by pressing the ink using a piezoelectric device or a heater, thereby printing a letter or picture on a printing paper. The ink jet device sprays ink, including dye ink, organic pigment, or carbon black through the nozzle in order to print a letter or picture while operating a printing head having a plurality of nozzles, thereby forming a minute dot in a paper. And, a set of minute dots records the letter or picture on the paper.  
         [0006]     Recently, it has been proposed to form wire lines and a spacer for a liquid crystal display panel by use of the ink jet device, especially, an ink jet device that uses a piezoelectric device that sends out ink and does not require a heating process.  
         [0007]     Further, the ink jet device that forms the wire line, spacer, etc. of the flat panel display panel forms the wire line and spacer by spraying material such as minute metal particles for the wire line and ball spacers for the spacers of the flat panel display panel. The discharged material includes solvent besides the minute metal particles and ball spacers that are the materials for forming the patterns of the wire line and spacer. The material for forming the patterns is mixed into the solvent, thereby being sprayed through the ink jet device.  
         [0008]     In the case where the material for forming the patterns is the minute metal particle, the discharged matter of the ink jet device is composed of the mixture of the solvent and the minute metal particle of 1-100 nm. In the case where the material for forming the patterns is the ball spacer, the discharged material of the ink jet device is composed of the mixture of the solvent and the ball spacer of 10 μm or less. To describe more specifically about the discharged material for forming the spacer, the ball spacer is made from a material of polystyrene, etc of 3-15 μm in diameter, and the solvent mixed with the ball spacer may include water, IPA (isopropyl alcohol), glycerol, etc.  
         [0009]     The discharged material is sprayed through the nozzles, thereby producing a desired pattern. The desired pattern is directed by a host computer (not shown) included in the ink jet device.  
         [0010]      FIG. 1  is a diagram briefly representing ink jet device of the related art, and an area ‘A’ of  FIG. 1  is illustrated for explaining an ink jet head more specifically.  
         [0011]     Referring to  FIG. 1 , the ink jet device for spraying the minute metal particles or the ball spacers includes an ink jet head  1  having a plurality of nozzles  9  that discharges a material, and a storing part  11  that stores the discharged material.  
         [0012]     Further, the ink jet device further includes: a pump  13  and a circulation path  23  that are formed between the storing part  11  and the ink jet head  1  in order to prevent precipitation and cohesion of the ball spacers or the minute metal particles of the discharged material stored at the storing part  11 ; first to third supply tubes  21 ,  22 ,  24  providing a passage through which the discharged material or cleaning water is supplied; a cleaning water supplier  15  that supplies the cleaning water for cleaning impurities or the precipitated minute particles of the inner part of the supply tube or the ink jet head part  1 ; a discharging part  17  for sending out the cleaning water including the precipitated minute particles; and first and second valves  31 ,  33  for controlling the flow of the cleaning water or the discharged material between the first to third supply tubes  21 ,  22 ,  24 .  
         [0013]     The storing part  11  acts to store the discharged material for the pattern to be formed.  
         [0014]     The storing part  11  is connected to the first supply tube  21  that provides a passage through which the discharged material may move, and the first supply tube  21  has the second valve  33  that determines whether or not the discharged material is discharged through the head part  1 .  
         [0015]     The discharged material stored at the storing part  11  moves to the ink jet head  1  along the first supply tube  21  and the third supply tube  24  that connects the first supply tube  21  and the ink jet head  1  when only the second valve  33  is opened.  
         [0016]     The ink jet head  1  further includes a collecting and delivering part  3  connected to the third supply tube  24  to accumulate the discharged material supplied from the storing part  11 ; a plurality of chambers  5  connected to the collecting and delivering part  3  to receive the discharged material accumulated at the collecting and delivering part  3 ; and a plurality of nozzles  9  connected to a plurality of chambers  5  to form a pattern by spraying the discharged material.  
         [0017]     The collecting and delivering part  3  acts to send out the discharged material transmitted from the third supply tube  24 .  
         [0018]     The chambers  5  act to cause the discharged material supplied from the collecting and delivering part  3  to be sprayed through the nozzle  9 . The piezoelectric device is adjacent to each of the chambers  5  in order to spray the discharged material through the nozzle  9 . Each of the piezoelectric devices is controlled by a host computer. In the ink jet device, when the piezoelectric device operates according to the control signal of the host computer, pressure is applied to the inside of the chamber  5 , and the discharged material inside of the chamber  5  is sprayed through the nozzle  9  by the pressure. The ink jet device may form a desired pattern through the sprayed discharged material, and the operation of the piezoelectric device is controlled in accordance with the desired pattern.  
         [0019]     On the other hand, the discharged material stored at the storing part  11  includes minute particles such as minute metal particles or ball spacers, thus if a long time lapses, the minute particles included in the discharged material might be precipitated or cohered. In order to prevent the precipitation and cohesion of the minute particles, the circulation path  23 . and the pump  13  are connected between the first supply tube  21  and the storing part  11 .  
         [0020]     The circulation path  23  is a stirring means which makes it possible for the discharged material stored at the storing part  11  to flow all the time. The minute particles included in the discharged material are prevented from precipitating or cohering by the circulation path  23  acting as a stirring means.  
         [0021]     The pump  13  acts to provide a driving force to the discharge material so that the discharged material stored at the storing part  11  moves through the circulation path  23 .  
         [0022]     Further, when using the ink jet device for a long time, the inside of the head part  1  may be contaminated with the precipitation, cohesion, adherence, etc. of the minute particles included in the discharged material. In order to remove the contaminant, an operator first closes the second valve  33  of the ink jet device and impedes the supply of the discharged material. Then, the operator opens the first valve  31  connected to the cleaning water supplier  15  so that the cleaning water can flow through the second supply tube  22  connected to the first valve  31  and the third supply valve  24  connected to the second supply valve  22 . The cleaning water is discharged to the outside by flowing along the collecting and delivering part  3  connected to the third supply tube  24 , the chamber  5  connected to the collecting and delivering part  3 , and the nozzle  9  connected to the chamber  5  through the third supply tube  24 . In this way, the cleaning water discharges the contaminant inside the head part  1  as the cleaning water is discharged to the outside through the head part  1 .  
         [0023]     In order to make the discharge of the contaminant more effective, the ink jet device might further include a discharging part  17  including a discharging tube  25  connected to the head part  1  and a third valve  35  connected to the discharging tube  25 .  
         [0024]     As described above, the ink jet device may eliminate the contaminant inside of the head part  1  by the cleaning water. The cleaning water flows by hydraulic pressure in the cleaning water supplier  15  to remove the contaminant. However, the hydraulic pressure applied to the cleaning water supplier  15  might damage the head part  1 , thus the strength of pressure that may be applied to the cleaning water supplier  15  is limited. Further, the pressure applied to the cleaning water supplier  15  can push out the contaminant only in a direction that the discharged material is sprayed. Because of the fact that the pressure applied for cleaning the head part  1  is provide only in the one direction that the discharged material is sprayed and that the strength is limited, the contaminant P resides behind at the corner inside of the chamber  5  and the collecting and delivering part  3 . There is a problem because the remaining contaminant P, when being left alone for a long time, causes the head part  1  to clog, thus shortening the life span of the ink jet device and then forming a bad pattern.  
       SUMMARY OF THE INVENTION  
       [0025]     Accordingly, the present invention is directed to an ink jet device that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.  
         [0026]     An advantage of the present invention is to provide an jet device that is adaptive for preventing formation of a bad pattern as well as improving the life span of the ink jet device.  
         [0027]     Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.  
         [0028]     In order to achieve these and other objects of the invention, an ink jet device according to an aspect of the present invention includes: a maintaining/repairing stage filled with cleaning water; a plurality of nozzles to be submerged into the maintaining/repairing stage filled with the cleaning water; a plurality of chambers connected to the nozzles in a one-to-one relationship, wherein a volume of each chamber is variable by a pressing means; a supply tube that supplies a discharged material; a discharging tube that discharges a contaminant and the cleaning water from at least one of the nozzle and the chamber; a collecting and delivering part connected to the supply tube, the discharging tube and the chambers that supplies the discharged material from the supply tube to the chambers and supplying the contaminant and the cleaning water from the chambers to the discharging tube; and a pump connected to the discharging tube that pumps the contaminant and the cleaning water to the discharging tube.  
         [0029]     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0030]     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.  
         [0031]     In the drawings:  
         [0032]      FIG. 1  is a diagram briefly representing ink jet device of the related art;  
         [0033]      FIG. 2  is a diagram briefly representing ink jet device according to the present invention; and  
         [0034]      FIG. 3  is a diagram representing a part of the ink jet device shown in  FIG. 2 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0035]     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.  
         [0036]     With reference to  FIGS. 2 and 3 , embodiments of the present invention will be explained as follows.  
         [0037]      FIG. 2  is a diagram briefly representing an ink jet device according to the present invention.  
         [0038]     Referring to  FIG. 2 , the ink jet device according to the present invention sends out a discharged material that is a mixture where minute particles are mixed into a liquid by a pressing means that uses a piezoelectric device or heater.  
         [0039]     The ink jet device might be used for forming wire lines of a flat panel display panel and spacers of a liquid crystal display panel. Especially, the ink jet device uses a piezoelectric device that sprays ink without a heating process.  
         [0040]     Further, in order to form the wire lines, spacers, etc. of the flat panel display panel, the ink jet device sprays a discharged material such as minute metal particles to form wire lines, ball spacers being a material for forming spacers, etc., thereby forming a wire line pattern and spacer. The discharged material has a solvent mixed thereinto except the minute metal particles and ball spacers that are the material for forming the patterns of the wire line and spacer. The materials for forming the patterns are mixed into the solvent so that they can be sprayed through the ink jet device.  
         [0041]     When the material for forming the patterns is the minute metal particles, the discharged material of the ink jet device is composed of a mixture of the minute metal particles a few nanometers m to several hundreds of nanometers in size and the solvent.  
         [0042]     When the material for forming the patterns is the ball spacer, the discharged material of the ink jet device is composed of a mixture of the ball spacers of ten micrometers or less and the solvent. More specifically, the ball spacer is made from a material such as polystyrene of 3˜15 μm in diameter, etc. The solvent mixed with the ball spacer may be composed of water, isopropyl alcohol IPA, glycerol, etc.  
         [0043]     The discharged material is sprayed through a plurality of nozzles, thus a desired pattern is patterned, wherein the desired pattern is directed by a host computer included in the ink jet device.  
         [0044]     Referring to  FIG. 2 , the ink jet device includes a head part  101  including a plurality of nozzles discharging a discharged material; and a storing part  111  for storing the discharged material.  
         [0045]     On the other hand, the discharged material for forming the pattern of the wire lines of the flat panel display panel or the spacer of the liquid crystal display panel as described above includes minute particles such as the minute metal particle or the ball spacer. Because the discharged material includes the minute particles and in order to prevent the minute particles included in the discharged material from being precipitated and cohered, the ink jet device includes a first pump  113  and a circulation path  123  between the storing part  111  and the head part  101 . The ink jet device according to the present invention further includes: a first cleaning water supplier  147  to supply cleaning water for cleaning the precipitated and adhered minute particles inside of the head part  101  in a reverse direction to the spraying of the discharged material; a maintaining/repairing stage  141  where the head part  101  may be submerged into liquid; and a first discharging part  117  for discharging cleaning water including the minute particles that are precipitated and cohered.  
         [0046]     The ink jet device according to the present invention might further include a second cleaning water supplier  115  for supplying the cleaning water for cleaning the precipitated and cohered minute particles in the same direction as the spraying of the discharged material.  
         [0047]     Referring to  FIG. 2  in conjunction with  FIG. 3 , the head part  101  includes: a collecting and delivering part  103  connected to a first supply tube  124  that supplies the discharged material supplied from the storing part  111  for accumulating the discharged material; a plurality of chambers  105  connected to the collecting and delivering part  103  to receive the discharged material accumulated at the collecting and delivering part  103 ; and a plurality of nozzles  109  connected to the plurality of chambers  105  to form a pattern by spraying the discharged material.  
         [0048]     The collecting and delivering part  103  sends out the discharged material supplied from the first supply tube  124  to the chambers  105  through a fluid path  107 A. Further, the collecting and delivering part  103  might be a stirring means as it is vibrated by a vibrating means so that the discharged material may maintain its uniformity.  
         [0049]     The chambers  105  cause the discharged material supplied from the collecting and delivering part  103  to be sent to the nozzle  109  through a fluid path  107 B, thereby spraying the discharged material through the nozzle  109 . The piezoelectric device is adjacent to each of the chambers  105  in order to spray the discharged material through the nozzle  109 . Each of the piezoelectric devices is controlled by the host computer to operate. If the piezoelectric device operates according to the control signal of the host computer, pressure is applied to the inside of the chamber  105 , and the discharged material inside the chamber  105  is sprayed through the nozzle  109  by the pressure. A desired pattern may be formed through the sprayed discharged material, and an operator only controls the operation of the piezoelectric device in accordance with the desired pattern.  
         [0050]     On the other hand, when using the ink jet device for a long time, the inside of the head part  101  might be contaminated as the minute particles included in the discharged material are precipitated, cohered and adhered. In order to remove the contaminant, an operator firstly closes the first valve  133  installed at a second supply tube  121  which connects the storing part  111  and the first supply tube  124  of the ink jet device, thereby preventing the discharged material from being supplied to the head part  101 . Then, the operator opens the second valve  131  installed at the second cleaning supply tube  122  that connects the second cleaning water supplier  115  and the first supply tube  124  so that the cleaning water supplied from the second cleaning water supplier  115  flows to the first supply tube  124  along the second cleaning water supply tube  122 . The cleaning water supplied from the second cleaning water supplier  115  is discharged from the head part  101  by flowing along the collecting and delivering part  103  connected to the first supply tube  124 , the chamber  105  connected to the collecting and delivering part  103 , and the nozzle  109  connected to the chamber  105  through the first supply tube  124 . In this way, the cleaning water discharges the contaminant inside of the head part  101  through the head part  101 . Further, the direction of discharging the contaminant inside the head part  101  with the cleaning water supplied from the second cleaning water supplier  115  is the same as the direction of discharging the discharged material.  
         [0051]     As described above, the contaminant discharged through the second cleaning supplier  115  is discharged in the direction of discharging the discharged material, thus the contaminant P residing in the corner of the inside of the collecting and delivering part  103  and the chamber  105  that are included in the head part  101  is hard to get rid of. Accordingly, in order to more effectively remove the contaminant of the inside of the head part  101 , especially, the contaminant residing in the corner of the inside of the chamber  105  and the collecting and delivering part  103 , the ink jet device according to the present invention includes: a first discharging part  117  connected to the head part  101  for discharging the contaminant; a maintaining/repairing stage  141  provided so that the head part  101  may be submerged into liquid; and a first cleaning water supplier  147  for supplying the cleaning water for removing the contaminant in the maintaining/repairing stage  141 .  
         [0052]     A method of removing the contaminant P residing in the corner inside the chamber  105  and the collecting and delivering part  103  through the first cleaning water supplier  147  will be described.  
         [0053]     In order to remove the contaminant P residing in the corner inside the chamber  105  and the collecting and delivering part  103 , the operator firstly closes the first and second valves  133 ,  131 . Because the first and second valves  133 ,  131  are closed, the discharged material flows into the head part  101  or the cleaning water is supplied from the second cleaning water supplier  115 . Then, the operator puts the head part  101  into the liquid in the maintaining/repairing stage  141 , and the cleaning water  155  may be supplied to the maintaining/repairing stage  141  from the first cleaning water supplier  147 . In order to supply the cleaning water  155  to the maintaining/repairing stage  141 , the maintaining/repairing stage  141  is connected to the first cleaning water supplier  147  through the first cleaning water supply tube  143 , and a third valve  151  is installed at the first cleaning water supplier  147 . The third valve  151  controls amount of the cleaning water supplied from the first cleaning water supplier  147  to supply the cleaning water to the maintaining/repairing stage  141 . The operator opens the third valve  151  so that the cleaning water  155  may be supplied to the maintaining/repairing stage  141 . As the third valve  151  is opened, the cleaning water supplied through the cleaning water supplier  147  is supplied to the maintaining/repairing stage  141  through the first cleaning water supply tube  143  to fill the maintaining/repairing stage  141 . The cleaning water  155  filled in the maintaining/repairing stage  141  is discharged along with the contaminant P residing in the corner of the inside of the chamber  105  and the collecting and delivering part  103  through the first discharging part  117  connected to the head part  101 .  
         [0054]     The first discharging part  117  includes: a first discharging tube  125  that is a path for the cleaning water including the contaminant P; a first pump  119  for applying pressure so that the cleaning water  155  of the maintaining/repairing stage  141  can be discharged through the first discharging part  117 ; and a third valve  135  disposed between the first pump  119  and the head part  101 .  
         [0055]     As described above, if the third valve  135  is opened and the first pump  119  is activated when the first and second valves  133 ,  131  are closed and the head part  101  is submerged into the maintaining/repairing stage  141  filled with the cleaning water  155 , the cleaning water  155  is drawn inside the head part  101  by the pressure applied through the first pump  119  of the maintaining/repairing stage  141 . The first pump  119  operates until the cleaning water  155  is discharged out of the head part  101  through the first discharging tube  125 .  
         [0056]     The contaminant P residing in the corner of the inside of the chamber  105  and the collecting and delivering part  103  is discharged along with the cleaning water  155  through the first discharging part  117  because it can float in the cleaning water  155  as the cleaning water  155  filled in the maintaining/repairing stage  141  is discharged in a direction opposite to spraying the discharged material by the operation of the second pump  119 .  
         [0057]     As described above, the ink jet device according to the present invention may get rid of the contaminant inside the head part  101  using the cleaning water  155 . Especially, the cleaning water  155  supplied to the maintaining/repairing stage  141  from the first cleaning water supplier  147  is pumped in the opposite direction of discharging the discharged material by use of the first discharging part  117 , thereby making it possible to effectively get rid of the contaminant P residing in the corner of the inside of the chamber  105  and the collecting and delivering part  103 .  
         [0058]     In this way, the ink jet device according to the present invention gets rid of contaminants in the head part  101  both in the direction of and in the reverse direction of discharging the discharged material, thereby enabling the removal of even the contaminant P residing in the corner of the inside of the chamber  105  and the collecting and delivering part  103 . Accordingly, the present invention may improve the life span of the ink jet device and prevent bad patterns from being formed because of a clogged head part  101  caused by contaminants P remaining for a long time in the corner inside the chamber  105  and the collecting and delivering part  103 . is prevented.  
         [0059]     Further, the ink jet device according to the present invention further includes a second discharging part  149  connected to the maintaining/repairing stage  141 .  
         [0060]     The second discharging part  149  includes a second discharging tube  145  providing a path for the cleaning water including the contaminant and a fifth valve  153  controlling the flow of the cleaning water. The cleaning water including the contaminant is discharged through the second discharging tube  145 .  
         [0061]     The ink jet device according to the present invention may be made to open the fifth valve  153  of the second discharging part  149  to discharge the cleaning water including of the contaminant through the second discharging part  149  when getting rid of the contaminant in the direction of discharging the discharged material.  
         [0062]     Further, the second discharging part  149  discharges the cleaning water  155  supplied to the maintaining/repairing stage  141  by opening the fifth valve  153 , thereby acting to prevent the cleaning water  155  supplied from the maintaining/repairing stage  141  from overflowing the maintaining/repairing stage  141 .  
         [0063]     On the other hand, the storing part  111  stores the discharged material to supplies the discharged material to the head part  101  when forming the pattern.  
         [0064]     The storing part  111  is connected to the second supply tube  121  that provides a passage through which the discharged material may travel, and the second supply tube  121  is connected to the first valve  133  that determines whether or not the discharged material is supplied to the head part  101 .  
         [0065]     The discharged material stored in the storing part  111  includes the minute particles, thus there is possibility that the minute particles included in the discharged material are precipitated or cohered as a long time passes. In order to prevent the precipitation and cohesion of the minute particles, a circulation path  123  is connected to the storing part  111 .  
         [0066]     The circulation path  123  is connected between the second supply tube  121  and the storing part  111 , thereby providing a stirring action that enables the discharged material stored in the storing part  111  to move freely all the time. The minute particles included in the discharged material are prevented from precipitating or cohering by the circulation path  123  providing a stirring action.  
         [0067]     Further, the circulation path  123  might include the first pump  113  providing a driving force so that the discharged material stored at the storing part  111  moves through the circulation path  123 .  
         [0068]     As described above, the ink jet device according to the present invention includes the first and second cleaning water supplier  147  that supplies the cleaning water  155 , thereby making it possible to get rid of the contaminant in the head part  101  in the direction of and in the reverse direction of discharging the discharged material. Thus it is possible to get rid of the contaminant residing in the corner inside the chamber and the collecting and delivering part. Accordingly, the ink jet device according to the present invention prevents the clogging of the head part  111  generated when the contaminant remaining in the corner inside the chamber and the collecting and delivering part  103  is left for a long time. As a result, it is possible that the life span of the ink jet device is improved and the formation of the bad pattern is prevented.  
         [0069]     Although the present invention has been explained by the embodiments shown in the drawings described above, it should be understood to the ordinary skilled person in the art that the invention is not limited to the embodiments, but rather that various changes or modifications thereof are possible without departing from the spirit of the invention. Accordingly, the scope of the invention shall be determined only by the appended claims and their equivalents.  
         [0070]     It will be apparent to those skilled in the art that various modifications and variations may be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.