Abstract:
The present disclosure provides an ink discharge device of a printing device. The ink discharge device contains a first cap, a second cap, and a pump. The first cap is utilized to cap a first nozzle area of the printing device has a first connecting terminal and a second connecting terminal. The second cap is utilized to cap a second nozzle area of the printing device has a third connecting terminal coupled to the second connecting terminal. The pump coupled to the first connecting terminal discharges the ink on the first and the second nozzle areas through the first and the second caps.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an ink discharge device, and especially to an ink discharge device capable of preventing a connecting terminal or a tube of a cap from becoming clogged.  
         [0003]     2. Description of the Prior Art  
         [0004]     Recently printers in the market place mostly contain an ink discharge device. The ink discharge device primarily utilizes a cap-carrying device to cover the nozzle of an inkjet head. The cap-carrying device is coupled to a tube, which has one terminal connected to the cap-carrying device and the other terminal connected to a pump. The pump discharges the air in the tube and the cap, which covers the inkjet head. As a result of the pump discharging action, a vacuum effect is achieved for the tube and the cap such that the ink in the inkjet head is drained out. As a result, the wet ink thereby pushes out the dry ink wherein the dry ink would otherwise cause clogging of the nozzle.  
         [0005]     There are several issues of importance that should be taken into consideration. Specifically, for example, care must be directed toward a cap design. Because the cap directly touches the ink, the material of the cap must, to a certain degree, possess an anti-chemical property. Moreover, the cap must also possess a good elasticity such that the cap can cover the inkjet head tightly in a sealed fashion. The cap can be designed in two ways. The cap can be designed as an enclosed cap or alternatively, with a hole on the cap. The primary purpose of the hole is to prevent any ink in the inkjet head from being pushed or forced back deeper into the inkjet head. For example, ink can be forced into the inkjet head by the compressed air in the cap when the cap is moving up to cover the inkjet head (i.e., when the cap is approaching the inkjet head. If the ink in the inkjet head is pushed/forced back deeper inside of the inkjet head, then it will become very difficult to clean the inkjet head. Care must be taken regarding the hole on the cap. The hole must be designed by following a defined specification of the inkjet head. Under basic conditions, wherein the pressure in the cap does not change when the cap is moving up to approach the inkjet head, the length and the cross section of the hole should be as long as possible and as small as possible to prevent the ink from evaporating to the environment.  
         [0006]     In the process of setting up an ink discharge device on a service station (or a maintenance station), every cap-carrying device must have a hole to be coupled to a tube, which is further connected to a pump. As mentioned above, the length and the cross section of the hole should be as long as possible and as small as possible to decrease the evaporation rate of the ink in the nozzle when the pump is not in operation. Please refer to  FIG. 1 .  FIG. 1  illustrates a diagram of a prior art cap. The cap  10  has a hole in the center utilized to discharge the air in the cap  10 . Please refer to  FIG. 2  for additional detail.  FIG. 2  illustrates a diagram of a side view of the cap  10 .  
         [0007]     Because the hole  12  on the cap  10  is very small, it is easy for said hole to become clogged. The dry ink has probably clogged the hole  12  if the composition of the ink discharged by the cap  10  is thick. Therefore, in this situation, the cap  10  is no longer able to clean the inkjet head that the cap  10  covers. As a result, the ink is subject to becoming thick or even dry out when the ink is exposed to the air. However, it is known that some ink is not subject to this drying phenomenon. More specifically, some ink will not become thick or even dry out when it is exposed to the air. For example, the most commonly utilized ink can be divided into two categories: a dye and a pigment. The dye ink will not leave behind residue or become sticky or thick after it is entirely evaporated; however, the pigment usually does become thick when it is exposed to the air. Therefore, the hole  12  of the cap  10  is probably clogged by the dry pigment.  
         [0008]     Please refer to  FIG. 3 .  FIG. 3  illustrates a diagram of a printer engine of a prior art ink-jet printer. The printer engine  100  primarily contains a main frame  110 , an inkjet head set  120 , a motor  130 , a lateral axis  140 , a feed axis  150 , a discharge axis  160 , a printing platform  170 , a scrape maintenance station  180 , a cap maintenance station  190 , and a pump  191 . The inkjet head set  120  has two inkjet heads  125  and  126  that are utilized for outputting ink. The primary function of the cap maintenance station  190  is to cover the inkjet heads  125  and  126  with caps  195  and  196  when the printer engine  100  will not be in operation for a long period of time. When the printer engine  100  is not in operation, the inkjet head set  120  moves to the cap maintenance station  190  along the lateral axis  140  under the drive of the motor  130 , as shown in  FIG. 4 .  FIG. 4  illustrates a diagram of the prior art ink-jet printer with the inkjet head set  120  on the cap maintenance station  190 . In this case, the caps  195  and  196  covers the inkjet heads  125  and  126  tightly to prevent the inkjet heads  125  and  126  from being exposed directly to the atmosphere thereby preventing the ink on the nozzles of the inkjet heads  125  and  126  to dry out and therefore clogs the nozzles.  
         [0009]     Please refer to  FIG. 5 , which is a simplified drawing of  FIG. 4 .  FIG. 5  illustrates a diagram of the configuration of the inkjet heads  125  and  126 , the cap maintenance station  190 , and the pump  191 . When the printer engine  100  will not be in operation for a long period of time, the inkjet heads  125  and  126  move to the cap maintenance station  190 . The cap maintenance station  190  has two tubes  193  and  194  connected to the pump  191 . Please refer to  FIG. 6 , which illustrates a diagram of a front view of the inkjet head  125  and  126  and the cap maintenance station  190 . The caps  195  and  195 , which respectively cover the inkjet heads  125  and  126 , are connected to the pump  191  respectively through the tubes  193  and  194 . When the pump  191  initiates operation, the pump  191  will discharge the air inside the caps  195  and  196  through the tubes  193  and  194 , causing a negative pressure in the caps  195  and  196 . As a result, the residual ink on the nozzles of the inkjet heads  125  and  126  is drained out, and therefore the inkjets  125  and  126  are cleaned.  
         [0010]     Please refer to  FIG. 7 .  FIG. 7  illustrates a diagram of the fine detailed parts of the cap maintenance station  190  and the connection between the pump  191  and the cap maintenance station  190  in greater detail. The cap maintenance station  190  has two caps  195  and  196  that are connected to the cap maintenance station  190  respectively through the springs  295  and  296 . The elastic force of the spring  295  and  296  push the caps  195  and  196  to ensure a close and fitting contact with the inkjet head  125  and  126 . In order to address the connection between the caps  195 ,  196 , and the pump  191  in more detail, the cap maintenance station  190 , the spring  295 , and  296  shown in  FIG. 7  are removed, and just remaining is the cap  195 ,  196 , tube  193 ,  194 , and the pump  191  as illustrated in  FIG. 8 .  FIG. 8  shows the first connection between the caps  195 ,  196 , and the pump  191 . As shown in  FIG. 8 , the cap  195  is connected to the pump  191  through the tube  193 , and the cap  196  is connected to the pump  191  through the tube  194 . That is, when the pump  191  is working, the pump  191  discharges the ink on the inkjet head  125  through the tube  193  and the cap  195 ; simultaneously, the pump  191  also discharges the ink on the inkjet head  126  through the tube  194  and the cap  196  to achieve the purpose of cleaning the inkjet head  125  and  126 . The connection shown in  FIG. 8  illustrates a diagram of the conventional connection manner utilized in the prior art. Please refer to  FIG. 9 .  FIG. 9  illustrates a diagram of the second connection between the caps  195 ,  196 , and the pump  191 . As shown in  FIG. 9 , the cap  195  and  196  are both connected to a “Y” type tube  200 . The “Y” type tube  200  has three openings, wherein two openings are respectively connected to the cap  195  and  196 , and the third opening is connected to the pump  191 . Therefore, the pump  191  can also achieve the objective of cleaning the inkjet head  125  and  126  while the pump  191  is in operation.  
         [0011]     As mentioned above, the most commonly utilized ink can be divided into two categories: a dye type ink and a pigment type ink. In the current market place for ink-based printers, the black color ink usually belongs to be pigment ink type. Additionally, in most of print devices used today, the usage frequency of the black color ink is greater relative to other ink colors, therefore, the hole of the cap  195  and  196  is probably more easily clogged by the dry pigment ink.  
       SUMMARY OF THE INVENTION  
       [0012]     It is therefore one of the objectives of the present invention to provide an ink discharge device to solve the above-mentioned problems.  
         [0013]     According to an aspect of the present invention, an ink discharge device of a printing device is disclosed. The ink discharge device of the printing device includes a first cap, a second cap, and a pump. The first cap is utilized for covering a first nozzle area of the printing device, and the first cap comprises a first connecting terminal and a second connecting terminal. The second cap is utilized for covering a second nozzle area of the printing device, and the second cap comprises a third connecting terminal coupled to the second connecting terminal. The pump is coupled to the first connecting terminal for discharging the ink on the first and the second nozzle areas through the first and the second caps.  
         [0014]     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  
       [0015]      FIG. 1  illustrates a diagram of a prior art cap.  
         [0016]      FIG. 2  illustrates a diagram of a side view of the prior art cap.  
         [0017]      FIG. 3  illustrates a diagram of a printer engine of a prior art ink-jet printer.  
         [0018]      FIG. 4  illustrates a diagram of the prior art ink-jet printer with the inkjet head positioned on the cap maintenance station.  
         [0019]      FIG. 5  illustrates a diagram of the configuration of the inkjet heads, the cap maintenance station, and the pump.  
         [0020]      FIG. 6  illustrates a diagram of a front view of the inkjet head and the cap maintenance station.  
         [0021]      FIG. 7  illustrates a diagram of the fine detailed parts of the cap maintenance station and the connection between the pump and the cap maintenance station.  
         [0022]      FIG. 8  illustrates a diagram of the first connection between the caps and the pump.  
         [0023]      FIG. 9  illustrates a diagram of the second connection between the caps and the pump.  
         [0024]      FIG. 10  illustrates a diagram of the connection between the cap and the pump according to a first embodiment of the present invention.  
         [0025]      FIG. 11  illustrates a diagram of the connection within three caps according to the third embodiment of the present invention.  
         [0026]      FIG. 12  illustrates a diagram of the connection within three caps according to the four embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0027]     Please refer to  FIG. 10 .  FIG. 10  illustrates a diagram that shows the connection between the cap and the pump according to a first embodiment of the present invention. As shown in  FIG. 10 , this embodiment includes two caps  220  and  230 . This embodiment of the present invention primarily differs from the prior art in that the cap  195  and  195  in the prior art have only one connecting terminal respectively. However, in this embodiment of the present invention, the cap  230  has two connecting terminals; one connecting terminal  232  is utilized for connecting the pump  210  through the tube  240 ; and the other connecting terminal  234  is utilized for connecting the cap  220 . The cap  220  has a connecting terminal  222 , which is connected to the connecting terminal  234  of the cap  230 . The connecting terminal  222  can be directly connected to the connecting terminal  234  to enforce the cap  220  and  230  connecting in a series without through any tube; or the cap  220  and  230  can be connected in a series through the tube  250  between the connecting terminal  222  and the connecting terminal  234 . Regardless of the details of being directly connected, for example, the caps  220  and  230  are connected directly, or through the tube  250 , the ultimate result is that the cap  230  is finally connected to the pump  210  through the tube  240 . Please assume that the cap  220  is utilized for covering a first inkjet head. Furthermore, please assume that the cap  230  is utilized for covering a second inkjet head. It can easily be seen that the pump  210  can discharge the residual ink on the nozzles of the first and the second inkjet heads through the tube  240 , the cap  230 , the tube  250 , and the cap  220  to achieve the cleaning purpose of the present invention.  
         [0028]     As is well known to those of average skilled in the art, the pigment usually becomes thick or sometimes even completely dry when it is exposed to the air, and therefore it is very easy for the hole of the cap to probably become clogged by the dry pigment. However, as mentioned earlier, the dye will not generate residue or stick (i.e., thicken) as a result of being entirely evaporated. Moreover, the result of experiments shows that when the pigment and dye are mixed; the above-mentioned shortage of the pigment will be alleviated. In other words, the shortage of pigment resulting from the evaporation action. That is, the mixed ink of the pigment and the dye is much more resilient to becoming thick or dried when it is exposed to the air; therefore the hole of the cap is rarely clogged due to the mixed ink solution.  
         [0029]     According to the results of the experiments, in practice, the first inkjet head, which here corresponds to the cap  220  of  FIG. 10 , will be utilized to output the dye; and the second inkjet head, which here corresponds to the cap  230 , will be utilized to output the dye or the pigment. Therefore, the ink in the connecting terminal  222 , the tube  250 , and the connecting terminal  234  will be the dye. As a result of this configuration it the clogging situation will not be happened. Additionally, an alternate configuration, for example, if the ink outputted from the second inkjet head is the dye, then the connecting terminal  232  and the tube  240  will again successfully avoid the clogging situation. Please consider the example wherein the ink outputted from the second inkjet head is the pigment. According to the present invention, the dye in the first inkjet head will be drained out according to the pump  210  through the connecting terminal  222 , tube  250 , the connecting terminal  234 , the connecting terminal  232  and the tube  240 ; and at the same time the pigment in the second inkjet head will be drained out according to the pump  210  through the connecting terminal  232  and the tube  240 . Therefore, the dye from the first inkjet head and the pigment from the second inkjet head will be mixed at the connecting terminal  232 . According to the above-mentioned result, the mixed ink is less likely (i.e., more resilient) to becoming thick and dried out; therefore, the connecting terminal  232  and the tube  240  will not become clogged.  
         [0030]     Moreover, the ink discharge device in the present invention is not limited to only two caps as described previously. Please refer to  FIG. 11 .  FIG. 11  illustrates a diagram of the connection within three caps according to the third embodiment of the present invention. As shown in  FIG. 11 , the connecting terminal  314  of the cap  310  is directly connected to the connecting terminal  322  of the cap  320 ; the other connecting terminal  324  of the cap  320  is directly connected to the connecting terminal  332  of the cap  330 ; and the connecting terminal  336  of the cap  330  is directly connected to the pump  210 . Additionally, please consider another situation by referring to  FIG. 12 .  FIG. 12  illustrates a diagram showing the connection within three caps according to the four embodiment of the present invention. In this embodiment, the connecting terminal  314  of the cap  310  is connected to the connecting terminal  322  of the cap  320  through the tube  410 ; the connecting terminal  324  of the cap  320  is connected to the connecting terminal  332  of the cap  330  through the tube  420 ; and the other connecting terminal  336  of the cap  330  is further connected to the pump  210 . Similarly, in order to avoid the situation of clogged ink of the connecting terminal and the tube, the ink corresponding to the last cap (e.g., the cap  310 ) should be the dye type ink, and the ink corresponding to the other caps then can be the dye type ink or the pigment type ink. Please note that, the number of cap are not limited in the present invention to those configurations disclosed here. That is, the disclosed configurations are offered as examples over and not meant to be limitations, and in other embodiments, more than three caps can be assigned with the same connecting manner depend on the design requirements at hand.  
         [0031]     In conclusion, the present invention can prevent a related connecting terminal or a related tube of a cap from being clogged according to ways of changing the connection between the cap and the pump and considering the characteristic of the ink.  
         [0032]     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.