Patent Publication Number: US-2005140764-A1

Title: Ink-jet printing apparatus

Description:
BACKGROUND OF THE INVENTION  
      1. Field of Invention  
      The invention relates to an ink-jet printing apparatus and, in particular, to an ink-jet printing apparatus applied for manufacturing organic light-emitting displays (OLED).  
      2. Related Art  
      The flat-panel displays have been developed based on the trend towards high brightness, planar and thinner structures, and power saving. Accordingly, the organic electroluminescent display panel is one of the most potential products in optoelectronics industries. The organic electroluminescent display panel uses the self-emitting feature of organic functional materials to perform display purposes. According to the molecular weight of the organic functional materials used in organic electroluminescent display panel, it could be distinguished into small molecule OLED (SM-OLED) panel and polymer light-emitting display (PLED) panel.  
      As shown in  FIG. 1 , the conventional organic electroluminescent display panel  6  comprises an anode substrate  61 , an organic functional layer  62 , and a cathode  63 . The organic functional layer  62  and the cathode  63  are formed, in sequence, on the anode substrate  61 , wherein the organic functional layer  62  is formed on the anode substrate  61  by an ink-jet printing method.  
      In the conventional ink-jet printing processes, the anode substrate  61  is manually moved into an ink-jet printing apparatus. The ink-jet printing apparatus comprises an ink-jet head, which is filled with an organic material such as a red-light electroluminescent material. The ink-jet head then prints the organic material on the anode substrate  61  as required. Next, another organic material, such as a blue-light electroluminescent material, is loaded, and the ink-jet head prints this organic material on the anode substrate  61  as required. After that, the above-mentioned steps can be repeated to print different organic materials on the anode substrate  61 .  
      In the previously mentioned processes, however, the manually moving not only wastes time and manpower, but also leads to the exposure of the organic electroluminescent display panel with air during the moving, which results in a shortened lifetime of the panel. In addition, the loaded organic materials pollute each other since the different organic materials may be loaded in the same ink-jet head. Moreover, it wastes time for loading the different organic materials.  
      It is therefore a subjective of the invention to provide an ink-jet printing apparatus for solving the above-mentioned problems.  
     SUMMARY OF THE INVENTION  
      In view of the foregoing, the invention is to provide an ink-jet printing apparatus, which is suitable for mass production and can prevent the pollution.  
      The invention is to provide an ink-jet printing apparatus, which has proper arrangements as required, so that the adjustment of the apparatus has better flexibility and the performance of the apparatus is improved.  
      The invention is to provide an ink-jet printing apparatus, which can prevent the jam of production line when a single apparatus is malfunction.  
      The invention is to provide an ink-jet printing apparatus, which can save the cost of manually moving, prevent the troubles caused by labor operations, and ensure the quality, lifetime and reliability of panels.  
      The invention is to provide an ink-jet printing apparatus, which is an automatic and integrated mass production apparatus, so that the throughput can be increased and the yield can be increased.  
      To achieve the above, an ink-jet printing apparatus of the invention, which is for printing at least one organic material on a substrate, comprises a delivering chamber, a loading mechanism, at least one ink-jet printing mechanism, a heat treatment process mechanism, and an unloading mechanism. The delivering chamber has a delivering unit for delivering the substrate. The loading mechanism connects to the delivering chamber, and the delivering unit carries the substrate from the loading mechanism. The ink-jet printing mechanism connects to the delivering chamber and prints the organic material on the substrate. The heat treatment process mechanism connects to the delivering chamber and heats the substrate with the printed organic material. The unloading mechanism connects to the delivering chamber, and the delivering unit carries the substrate to the unloading mechanism.  
      To achieve the above, an ink-jet printing apparatus of the invention, which is for printing at least one organic material on a substrate, comprises a loading device, at least one ink-jet printing device, an unloading device, a plurality of heat treatment process devices, and a plurality of cooling devices. The loading device comprises a first delivering chamber and a loading chamber connecting to the first delivering chamber. The ink-jet printing device comprises at least one first ink-jet printing chamber and a second delivering chamber connecting to the first ink-jet printing chamber. The second delivering chamber connects to the first delivering chamber. The unloading device comprises a third delivering chamber and an unloading chamber connecting to the third delivering chamber. The third delivering chamber connects to the second delivering chamber. The heat treatment process devices are respectively disposed between the first delivering chamber and the second delivering chamber and between the second delivering chamber and the third delivering chamber. The cooling devices are respectively disposed between the first delivering chamber and the second delivering chamber and between the second delivering chamber and the third delivering chamber.  
      To achieve the above, an ink-jet printing apparatus of the invention, which is for printing at least one organic material on a substrate, comprises a loading device, a plurality of ink-jet printing devices, an unloading mechanism, a plurality of heat treatment process devices, and a plurality of cooling devices. The loading device comprises a first delivering chamber and a loading chamber connecting to the first delivering chamber. The ink-jet printing device comprises at least one first ink-jet printing chamber and a second delivering chamber connecting to the first ink-jet printing chamber. The second delivering chambers connect to one another. The unloading mechanism comprises a third delivering chamber and an unloading chamber connecting to the third delivering chamber. One of the second delivering chambers connects to the third delivering chamber, and one of the second delivering chambers connects to the first delivering chamber. The heat treatment process devices are respectively disposed between the first delivering chamber and the second delivering chambers, between the second delivering chambers and the third delivering chamber, and between every two of the second delivering chambers. The cooling devices are respectively disposed between the first delivering chamber and the second delivering chambers, between the second delivering chambers and the third delivering chamber, and between every two of the second delivering chambers.  
      To achieve the above, an ink-jet printing apparatus of the invention, which is for printing at least one organic material on a substrate, comprises a loading device, a plurality of ink-jet printing devices, an unloading mechanism, a plurality of heat treatment process devices, and a plurality of cooling devices. The loading device comprises a first delivering chamber and a loading chamber connecting to the first delivering chamber. The ink-jet printing device comprises a plurality of second delivering chambers and a plurality of first ink-jet printing chambers. The second delivering chamber connects to at least one of the first ink-jet printing chambers, and the second delivering chambers connect to one another. The unloading mechanism comprises a third delivering chamber and an unloading chamber connecting to the third delivering chamber. One of the second delivering chambers of the ink-jet printing device connects to the third delivering chamber, and one of the second delivering chambers of the ink-jet printing device connects to is the first delivering chamber. The heat treatment process devices are respectively disposed between the first delivering chamber and the second delivering chambers, between the second delivering chambers and the third delivering chamber, and between every two of the second delivering chambers. The cooling devices are respectively disposed between the first delivering chamber and the second delivering chambers, between the second delivering chambers and the third delivering chamber, and between every two of the second delivering chambers.  
      To achieve the above, an ink-jet printing apparatus of the invention, which is for printing at least one organic material on a substrate, comprises a delivering chamber, at least one ink-jet printing mechanism, and a heat treatment process mechanism. The delivering chamber comprises a delivering unit for delivering the substrate. The ink-jet printing mechanism connects to the delivering chamber and prints the organic material on the substrate. The heat treatment process mechanism connects to the delivering chamber and heats the substrate with the printed organic material.  
      As mentioned above, the ink-jet printing apparatus of the invention has proper arrangements as required. Comparing with the conventional art, the invention can change the number of the ink-jet printing device (ink-jet printing mechanism) and the positions and number of other devices (mechanisms) according to different situations. Thus, the adjustment of the apparatus has better flexibility. For example, when the throughput of the current apparatus is insufficient, the additional ink-jet print chambers (ink-jet print mechanisms) can be installed on the delivering chamber. This can increase the throughput without ordering another apparatus for larger throughput. In addition, when one ink-jet printing device is malfunction, other ink-jet print devices can keep working. Moreover, the organic material is printed in the assigned ink-jet print chamber (ink-jet print mechanism), so time for changing the material can be saved and the pollution of the different organic materials can be prevented. Furthermore, the manually moving is unnecessary in the ink-jet print processes of the invention, so not only the time cost for the manual operation can be saved, but also the organic electroluminescent panel can be prevented from the air, which results in the dark spots. Therefore, the lifetime and reliability of the panel can be assured. In addition, since ink-jet printing apparatus of the invention an automatic and integrated mass production apparatus, so that the throughput can be increased and the yield can be greatly increased. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The invention will become more fully understood from the detailed description given hereinbelow illustration only, and thus is not limitative of the present invention, and wherein:  
       FIG. 1  is a schematic view showing the conventional organic electroluminescent display panel;  
       FIG. 2  is a schematic view showing an ink-jet printing apparatus according to a first embodiment of the invention;  
       FIG. 3  is a schematic view showing an ink-jet printing apparatus according to a second embodiment of the invention;  
       FIG. 4  is a schematic view showing an ink-jet printing apparatus according to a third embodiment of the invention;  
       FIG. 5  is a schematic view showing an ink-jet printing apparatus according to a fourth embodiment of the invention;  
       FIG. 6  is a schematic view showing an ink-jet printing apparatus according to a fifth embodiment of the invention; and  
       FIG. 7  is a schematic view showing an ink-jet printing apparatus according to a sixth embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.  
     First Embodment  
      With reference to  FIG. 2 , an ink-jet printing apparatus  1  according to the first embodiment of the invention, which is for printing at least one organic material on a substrate, comprises a delivering chamber  11 , a loading mechanism  12 , at least one ink-jet printing mechanism  13 , a heat treatment process mechanism  14 , and an unloading mechanism  15 . In the embodiment, the delivering chamber  11  has a delivering unit  111  for delivering the substrate. The loading mechanism  12  connects to the delivering chamber  11 , and the delivering unit  111  carries the substrate from the loading mechanism  12 . The ink-jet printing mechanism  13  connects to the delivering chamber  11  and prints the organic material on the substrate. The heat treatment process mechanism  14  connects to the delivering chamber  11  and heats the substrate with the printed organic material. The unloading mechanism  15  connects to the delivering chamber  11 , and the delivering unit  111  carries the substrate to the unloading mechanism  15 .  
      In the embodiment, the substrate is an electrode substrate, such as an ITO (indium-tin oxide) substrate, an AZO (aluminum-zinc oxide) substrate, or an IZO (indium-zinc oxide) substrate. Of course, the electrode substrate can be a substrate having a surface formed with a metal.  
      In the present embodiment, the delivering chamber  11  can be a polygon configuration structure, such as an octagon configuration structure as shown in  FIG. 2 . Of course, the delivering chamber  11  can be any shaped configuration structure, such as an irregular shaped configuration structure as shown in  FIG. 4 . The delivering unit  111  can be a robot arm, a transporting axle or a transporting belt. When performing the ink-jet printing processes, the substrate is moved to the ink-jet printing mechanism  13 , the heat treatment process mechanism  14 , or the unloading mechanism  15  with the delivering unit  111 . Accordingly, an ink-jet printing process, a heat treatment process, or an unloading process can be performed.  
      The organic materials are very sensitive to moisture and oxygen, so that dark spots may be formatted when the materials contact with air. Therefore, the delivering chamber  11  is capable of exhausting air to provide vacuum or then to fill with inert gas as required. Thus, the processes can be performed under vacuum or inert gas environment, so that the dark spots can be decreased. The exhausting system (not shown) of the delivering chamber  11  may comprise a rotary pump, a mechanical pump, a turbo molecular pump, or a low-temperature pump. In this case, the delivering chamber  11  can reach vacuum state in a short time.  
      In addition, the delivering chamber  11  may further comprise a gate, which comprises a valve  19 . Herein, the gate is used for installing additional mechanisms, so that the ink-jet printing apparatus  1  can be changed any time to match the throughput requirement of different situations.  
      Referring to  FIG. 2  again, the loading mechanism  12  connects to the delivering chamber  11 , and the delivering unit  111  can carry the substrate from the loading mechanism  12 . In this embodiment, the substrate is positioned in the loading mechanism  12 , and the delivering unit  111  then carries the substrate to other mechanisms for the later processes.  
      In addition, as shown in  FIG. 2 , the ink-jet printing mechanism  13  connects to the delivering chamber  11 , and prints the organic material on the substrate. Herein, the ink-jet printing mechanism  13  comprises an ink-jet printing unit (not shown) and a material storage unit (not shown). When the ink-jet printing mechanism  13  works, the ink-jet printing unit prints the organic material stored in the material storage unit to the substrate. As shown in  FIG. 2 , there are two ink-jet printing mechanisms  13  in this case, and the ink-jet printing unit prints different organic material on the substrate. Herein, the pollution of changing different organic materials as described in the conventional art can be prevented.  
      In addition, the organic material of the embodiment can be the same material for forming a buffer layer, such as a hole-injecting layer, a hole-transporting layer, an electroluminescent layer, an electron-transporting layer or an electron-injecting layer. Alternatively, the organic material of the embodiment can be the same material for forming an electroluminescent layer, which can emit light such as blue light, green light, red light, white light, or other monochromatic light.  
      With reference to  FIG. 2 , the heat treatment process mechanism  14  connects to the delivering chamber  11  and heats the substrate with the printed organic material. The heat treatment process mechanism  14  provides heat to evaporate the organic solvent, so that the process time can be shortened. In the embodiment, the heat treatment process mechanism  14  comprises a heating unit and a heat controller (not shown). The heating unit can be a hot plate or an oven. Take the hot plate as an example, the hot plate has a platform with an internal pipe, and the pipe is filled with a fluid for changing the temperature of the platform. For example, the fluid can be water, and the heat controller can transfer the water of different temperature to the pipe for adjusting the temperature of the platform. Alternatively, the hot plate may have a platform with an internal heating coil, which can transform the electronic energy into heat for increasing the temperature of the platform.  
      In addition, the heat treatment process mechanism  14  may further comprise an exhausting-charging unit. When the organic solvent is evaporated, the exhausting-charging unit can exhaust air of the heat treatment process mechanism  14  for providing vacuum. Then, the exhausting-charging unit can charge inert gas into the heat treatment process mechanism  14  to maintain it in a constant atmosphere.  
      As shown in  FIG. 2 , the unloading mechanism  15  connects to the delivering chamber  11 , and the delivering unit  111  carries the substrate to the unloading mechanism  15  from other mechanisms.  
      With reference to  FIG. 2 , the ink-jet printing apparatus  1  of the embodiment further comprises a cooling mechanism  16 , which connects to the delivering chamber  11  and cools the substrate treated by the heat treatment process. This can shorten the waiting time for cooling the substrate. In the embodiment, the cooling mechanism  16  comprises a cooling unit and a cool controller (not shown). The cooling unit can be a cool plate. Take the cool plate as an example, the cool plate has a platform with an internal pipe, and the pipe is filled with a fluid for changing the temperature of the platform. For example, the fluid can be water, and the cool controller can transfer the water of different temperature to the pipe for adjusting the temperature of the platform.  
      As shown in  FIG. 2 , the ink-jet printing apparatus  1  of the embodiment further comprises a pre-treatment mechanism  17 , which connects to the delivering chamber  11 . The pre-treatment mechanism  17  is used to clean the substrate by, for example, plasma cleaning.  
      In the embodiment, with reference to  FIG. 2 , a plurality of valves  18  are provided, and the valve is disposed between the delivering chamber  11  and the loading mechanism  12 , the ink-jet printing mechanism  13 , the heat treatment process mechanism  14 , the cooling mechanism  16 , the pre-treatment mechanism  17  and the unloading mechanism  15 . The valves  18  can isolate the atmosphere between the mechanisms.  
     Second Embodiment  
      With reference to  FIG. 3 , an ink-jet printing apparatus  2  according to the second embodiment of the invention, which is for printing at least one organic material on a substrate, comprises a loading device  21 , at least one ink-jet printing device  22 , an unloading device  23 , a plurality of heat treatment process devices  24  and a plurality of cooling devices  25 . In the embodiment, the loading device  21  comprises a first delivering chamber  211  and a loading chamber  212  connecting to the first delivering chamber  211 . The ink-jet printing device  22  comprises at least one first ink-jet printing chamber  221  and a second delivering chamber  222  connecting to the first ink-jet printing chamber  221 . The second delivering chamber  222  connects to the first delivering chamber  211 . The unloading device  23  comprises a third delivering chamber  231  and an unloading chamber  232  connecting to the third delivering chamber  231 . The third delivering chamber  231  connects to the second delivering chamber  222 . The heat treatment process devices  24  are respectively disposed between the first delivering chamber  211  and the second delivering chamber  222 , and between the second delivering chamber  222  and the third delivering chamber  231 . The cooling devices  25  are respectively disposed between the first delivering chamber  211  and the second delivering chamber  222  and between the second delivering chamber  222  and the third delivering chamber  231 .  
      As shown in  FIG. 3 , the first delivering chamber  211 , the second delivering chamber  222  and the third delivering chamber  231  further comprises at least one gate, and the gate comprises a valve  27 . Herein, the gate is used for installing additional chambers, so that the ink-jet printing apparatus  2  can be changed any time to match the throughput requirement and process changing of different situations.  
      Referring to  FIG. 3 , the loading device  21  further comprises at least one second ink-jet printing chamber  213  connecting to the first delivering chamber  211 .  
      The unloading device  23  further comprises at least one third ink-jet printing chamber  233  connecting to the third delivering chamber  231 .  
      In the embodiment, the features and functions of the first delivering chamber  211 , the second delivering chamber  222  and the third delivering chamber  231  are the same to the delivering chamber  11  described in the first embodiment, the features and functions of the loading chamber  212  are the same to the loading mechanism  12  described in the first embodiment, the features and functions of the first ink-jet printing chamber  221 , the second ink-jet printing chamber  213  and the third ink-jet printing chamber  233  are the same to the ink-jet printing mechanism  13  described in the first embodiment, the features and functions of the heat treatment process devices  24  and the cooling devices  25  are the same to the heat treatment process mechanism  14  and the cooling mechanism  16  described in the first embodiment, and the features and functions of the unloading chamber  232  are the same to the unloading mechanism  15  described in the first embodiment, so the detailed descriptions are omitted here for concise purpose.  
      The organic material to be printed on the substrate of the embodiment is the same to that described in the first embodiment, so the detailed descriptions are omitted here for concise purpose.  
      In the present embodiment, the unloading device  23  further comprises an annealing unit  234  for annealing the substrate. Herein, the annealing unit  234  is a hot plate or an oven. In the embodiment, whether the annealing process is performed or not is determined according to the characteristic of the organic material. In addition, the unloading device  23  may further comprise a cooler  234 .  
      As shown in  FIG. 3 , a plurality of valves  26  are provided, and the valve  26  is disposed on the interfaces of the first delivering chamber  211 , the loading chamber  212 , the first ink-jet printing chamber  221 , the second ink-jet printing chamber  213 , the third ink-jet printing chamber  233 , the second delivering chamber  222 , the third delivering chamber  231 , the unloading chamber  232 , the heat treatment process devices  24  and the cooling devices  25 . Of course, the valve can be removed from where between the cooling devices  25  and the first delivering chamber  211 , the second delivering chamber  222  and the third delivering chamber  231 .  
      In the current embodiment, a delivering unit of the first delivering chamber  211  carries the substrate from the loading chamber  212  and carries it to the second ink-jet printing chamber  213 . In the second ink-jet printing chamber  213 , an organic material, such as a buffer layer, is printed on the substrate. The delivering unit of the first delivering chamber  211  then carries the substrate with the printed organic material from the second ink-jet printing chamber  213  to the heat treatment process device  24 . The heat treatment process device  24  heats the substrate to remove the organic solvent, wherein the heat treatment process device  24  is exhausted to obtain vacuum and is then filled with inert gas to maintain itself in a constant atmosphere. A delivering mechanism, such as a robot arm, is installed between the heat treatment process device  24  and the cooling device  25 , and carries the substrate treated by the heat treatment process from the heat treatment process device  24  to the cooling device  25  for cooling. Then, a delivering unit of the second delivering chamber  222  carries the substrate from the cooling device  25  to the first ink-jet printing chamber  221 . In the first ink-jet printing chamber  221 , another organic material, such as an electroluminescent layer, is printed on the substrate formed with the buffer layer. The delivering unit of the second delivering chamber  222  then carries the substrate formed with the buffer layer and electroluminescent layer from the first ink-jet printing chamber  221  to the heat treatment process device  24 . The heat treatment process device  24  heats the substrate to remove the organic solvent, wherein the heat treatment process device  24  is exhausted to obtain vacuum and is then filled with inert gas to maintain itself in a constant atmosphere. A delivering mechanism, such as a robot arm, is installed between the heat treatment process device  24  and the cooling device  25 , and carries the substrate treated by the heat treatment process from the heat treatment process device  24  to the cooling device  25  for cooling. Then, a delivering unit of the third delivering chamber  231  carries the substrate from the cooling device  25  to the third ink-jet printing chamber  233 . In the third ink-jet printing chamber  233 , an additional ink-jet process is performed. Finally, a delivering unit of the third delivering chamber  231  carries the substrate to the unloading device  232  for unloading operations.  
      Of course, the substrate can be delivered between the heat treatment process device  24  and the cooling device  25  by the delivering unit of the first delivering chamber  211 , the second delivering chamber  222 , or the third delivering chamber  231 .  
      In addition, except for heat treatment and cool treatment, the heat treatment process device  24  and the cooling device  25  of the embodiment can be also used as delivering chambers.  
     Third Embodiment  
      With reference to  FIG. 4 , except for that there are two ink-jet printing devices  22  in the embodiment, other elements are the same to those of the second embodiment. The features and functions of the individual element are the same to those of the second embodiment described previously, so the detailed descriptions are omitted here for concise purpose.  
      In addition, one of the second delivering chambers  222  of the embodiment has irregular shaped configuration structure.  
      In the present embodiment, when one of the ink-jet printing devices  22  is malfunctioned and should be stopped, the operator can continuously perform the ink-jet printing process with other ink-jet printing device  22 . Thus, the malfunctioned ink-jet printing device  22  would not lead to the stop of the whole ink-jet printing apparatus  2 . Of course, both the ink-jet printing devices  22  can be operated at the same time, so as to increase the total throughput.  
      Of course, the ink-jet printing apparatus  2  can comprise a plurality of ink-jet printing devices  22  as required.  
     Fourth Embodiment  
      With reference to  FIG. 5 , an ink-jet printing apparatus  3  according to the fourth embodiment of the invention, which is for printing at least one organic material on a substrate, comprises a loading device  31 , a plurality of ink-jet printing devices  32 , an unloading device  33 , a plurality of heat treatment process devices  34  and a plurality of cooling devices  35 . The loading device  31  comprises a first delivering chamber  311  and a loading chamber  312  connecting to the first delivering chamber  311 . The ink-jet printing device  32  comprises at least one first ink-jet printing chamber  321  and a second delivering chamber  322  connecting to the first ink-jet printing chamber  321 . The second delivering chambers  322  connect to one another. The unloading device  33  comprises a third delivering chamber  331  and an unloading chamber  332  connecting to the third delivering chamber  331 . One of the second delivering chambers  322  connects to the third delivering chamber  331 , and one of the second delivering chambers  322  connects to the first delivering chamber  311 . The heat treatment process devices  34  are respectively disposed between the first delivering chamber  311  and the second delivering chambers  322 , between the second delivering chambers  322  and the third delivering chamber  331 , and between every two of the second delivering chambers  322 . The cooling devices  35  are respectively disposed between the first delivering chamber  311  and the second delivering chambers  322 , between the second delivering chambers  322  and the third delivering chamber  331 , and between every two of the second delivering chambers  322 .  
      As shown in  FIG. 5 , the first delivering chamber  311 , the second delivering chamber  322  and the third delivering chamber  331  further comprises at least one gate, and the gate comprises a valve  37 . Herein, the gate is used for installing additional chambers, so that the ink-jet printing apparatus  3  can be changed any time to match the throughput requirement and process changing of different situations.  
      Referring to  FIG. 5 , the loading device  31  further comprises at least one second ink-jet printing chamber  313  connecting to the first delivering chamber  311 .  
      The unloading device  33  further comprises at least one third ink-jet printing chamber  333  connecting to the third delivering chamber  331 .  
      In the embodiment, the features and functions of the first delivering chamber  311 , the second delivering chamber  322  and the third delivering chamber  331  are the same to the delivering chamber  11  described in the first embodiment, the features and functions of the loading chamber  312  are the same to the loading mechanism  12  described in the first embodiment, the features and functions of the first ink-jet printing chamber  321 , the second ink-jet printing chamber  313  and the third ink-jet printing chamber  333  are the same to the ink-jet printing mechanism  13  described in the first embodiment, the features and functions of the heat treatment process devices  34  and the cooling devices  35  are the same to the heat treatment process mechanism  14  and the cooling mechanism  16  described in the first embodiment, and the features and functions of the unloading chamber  332  are the same to the unloading mechanism  15  described in the first embodiment, so the detailed descriptions are omitted here for concise purpose.  
      The organic material to be printed on the substrate of the embodiment is the same to that described in the first embodiment, so the detailed descriptions are omitted here for concise purpose.  
      In the present embodiment, the unloading device  33  further comprises an annealing unit  334  for annealing the substrate. Herein, the annealing unit  334  is a hot plate or an oven. In the embodiment, whether the annealing process is performed or not is determined according to the characteristic of the organic material. As shown in  FIG. 4 , the annealing unit  334  is an oven.  
      As shown in  FIG. 5 , a plurality of valves  36  are provided, and the valve  36  is disposed on the interfaces of the first delivering chamber  311 , the loading chamber  312 , the first ink-jet printing chamber  321 , the second ink-jet printing chamber  313 , the third ink-jet printing chamber  333 , the second delivering chamber  322 , the third delivering chamber  331 , the unloading chamber  332 , the heat treatment process devices  34  and the cooling devices  35 . Of course, the valve can be removed from where between the cooling devices  35  and the first delivering chamber  311 , the second delivering chamber  322  and the third delivering chamber  331 .  
      In the current embodiment, a delivering unit of the first delivering chamber  311  carries the substrate from the loading chamber  312  and carries it to the second ink-jet printing chamber  313 . In the second ink-jet printing chamber  313 , an organic material, such as a red light material, is printed on the substrate. The delivering unit of the first delivering chamber  311  then carries the substrate with the printed organic material from the second ink-jet printing chamber  313  to the heat treatment process device  34 . The heat treatment process device  34  heats the substrate to remove the organic solvent, wherein the heat treatment process device  34  is exhausted to obtain vacuum and is then filled with inert gas to maintain itself in a constant atmosphere. A delivering mechanism, such as a robot arm, is installed between the heat treatment process device  34  and the cooling device  35 , and carries the substrate treated by the heat treatment process from the heat treatment process device  34  to the cooling device  35  for cooling. Then, a delivering unit of the second delivering chamber  322  carries the substrate from the cooling device  35  to the first ink-jet printing chamber  321 . In the first ink-jet printing chamber  321 , another organic material, such as a green light material, is printed on the substrate. The delivering unit of the second delivering chamber  322  then carries the substrate formed with the green light material from the first ink-jet printing chamber  321  to the heat treatment process device  34 . The heat treatment process device  34  heats the substrate to remove the organic solvent, wherein the heat treatment process device  34  is exhausted to obtain vacuum and is then filled with inert gas to maintain itself in a constant atmosphere. A delivering mechanism, such as a robot arm, is installed between the heat treatment process device  34  and the cooling device  35 , and carries the substrate treated by the heat treatment process from the heat treatment process device  34  to the cooling device  35  for cooling. Then, a delivering unit of another second delivering chamber  322 ′ carries the substrate from the cooling device  35  to the another first ink-jet printing chamber  321 ′. In the first ink-jet printing chamber  321 ′, another organic material, such as a blue light material, is printed on the substrate. The delivering unit of the second delivering chamber  322 ′ then carries the substrate formed with the blue light material from the first ink-jet printing chamber  321 ′ to the heat treatment process device  34 . The heat treatment process device  34  heats the substrate to remove the organic solvent, wherein the heat treatment process device  34  is exhausted to obtain vacuum and is then filled with inert gas to maintain itself in a constant atmosphere. A delivering mechanism, such as a robot arm, is installed between the heat treatment process device  34  and the cooling device  35 , and carries the substrate treated by the heat treatment process from the heat treatment process device  34  to the cooling device  35  for cooling. Then, an additional first ink-jet printing device  321 ″, an additional second delivering chamber  322 ″, the third ink-jet printing chamber  333  and the third delivering chamber  331  are employed to repeat the above-mentioned steps. Finally, the substrate is carried to the unloading device  332  for unloading operations.  
      Of course, the substrate can be carried between the heat treatment process device  34  and the cooling device  35  by the delivering unit of the first delivering chamber  311 , the second delivering chambers  322 ,  322 ′,  322 ″, or the third delivering chamber  331 .  
      In the current embodiment, the ink-jet printing apparatus  3  can comprise a plurality of ink-jet printing devices  32  as required.  
     Fifth Embodiment  
      With reference to  FIG. 6 , an ink-jet printing apparatus  4  according to the fifth embodiment of the invention, which is for printing at least one organic material on a substrate, comprises a loading device  41 , a plurality of ink-jet printing devices  42 , an unloading mechanism  43 , a plurality of heat treatment process devices  44  and a plurality of cooling devices  45 . The loading device  41  comprises a first delivering chamber  411  and a loading chamber  412  connecting to the first delivering chamber  411 . The ink-jet printing device  42  comprises a plurality of second delivering chambers  422  and a plurality of first ink-jet printing chambers  421 . The second delivering chamber  422  connects to at least one of the first ink-jet printing chambers  421 , and the second delivering chambers  422  connect to one another. The unloading device  43  comprises a third delivering chamber  431  and an unloading chamber  432  connecting to the third delivering chamber  431 . One of the second delivering chambers  422  of the ink-jet printing device  42  connects to the third delivering chamber  431 , and one of the second delivering chambers  422  of the ink-jet printing device  42  connects to is the first delivering chamber  411 . The heat treatment process devices  44  are respectively disposed between the first delivering chamber  411  and the second delivering chambers  422 , between the second delivering chambers  422  and the third delivering chamber  431 , and between every two of the second delivering chambers  422 . The cooling devices  45  are respectively disposed between the first delivering chamber  411  and the second delivering chambers  422 , between the second delivering chambers  422  and the third delivering chamber  431 , and between every two of the second delivering chambers  422 .  
      The first delivering chamber  411 , the second delivering chambers  422  and the third delivering chamber  431  further comprises at least one gate, and the gate comprises a valve  47 .  
      The loading device  41  further comprises at least one second ink-jet printing chamber  413  connecting to the first delivering chamber  411 . The unloading device  43  further comprises at least one third ink-jet printing chamber  433  connecting to the third delivering chamber  431 .  
      The organic material to be printed on the substrate of the embodiment is the same to that described in the first embodiment, so the detailed descriptions are omitted here for concise purpose.  
      In this embodiment, the unloading device  43  further comprises an annealing unit  434  for annealing the substrate. Herein, the annealing unit  434  is a hot plate or an oven.  
      As shown in  FIG. 6 , a plurality of valves  46  are provided, and the valve  46  is disposed on the interfaces of the first delivering chamber  411 , the loading chamber  412 , the first ink-jet printing chamber  421 , the second ink-jet printing chamber  413 , the third ink-jet printing chamber  433 , the second delivering chamber  422 , the third delivering chamber  431 , the unloading chamber  432 , the heat treatment process devices  44  and the cooling devices  45 . Of course, the valve can be removed from where between the cooling devices  45  and the first delivering chamber  411 , the second delivering chambers  422  and the third delivering chamber  431 .  
      Of course, the substrate can be carried between the heat treatment process device  44  and the cooling device  45  by the delivering unit of the first delivering chamber  411 , the second delivering chambers  422 , or the third delivering chamber  431 .  
      With reference to  FIG. 6 , except for that there are eight ink-jet printing devices  42  in the embodiment, other elements are the same to those of the fourth embodiment. The features and functions of the individual element are the same to those of the fourth embodiment described previously, so the detailed descriptions are omitted here for concise purpose.  
      In the present embodiment, when one of the ink-jet printing devices  42  is malfunctioned and should be stopped, the operator can continuously perform the ink-jet printing process with other ink-jet printing devices  42 . Thus, the malfunctioned ink-jet printing device  42  would not lead to the stop of the whole ink-jet printing apparatus  4 . Of course, dual lines ink-jet printing devices  42  can be provided and operated at the same time, so as to increase the total throughput.  
      Of course, the ink-jet printing apparatus  4  can comprise a plurality of ink-jet printing devices  42  as required.  
     Sixth Embodiment  
      With reference to  FIG. 7 , an ink-jet printing apparatus  5  according to the sixth embodiment of the invention, which is for printing at least one organic material on a substrate, comprises a delivering chamber  51 , at least one ink-jet printing mechanism  52  and a heat treatment process mechanism  53 . The delivering chamber  51  comprises a delivering unit  511  for delivering the substrate. The ink-jet printing mechanism  52  connects to the delivering chamber  51  and prints the organic material on the substrate. The heat treatment process mechanism  53  connects to the delivering chamber  51  and heats the substrate with the printed organic material.  
      In the embodiment, the ink-jet printing apparatus  5  further comprises a loading mechanism  54 , an unloading mechanism  55 , a cooling mechanism  56 , a pre-treatment mechanism  57  and valves  58 ,  59 . The features and functions of these elements are the same to those same element described in the first embodiment, so the detailed descriptions are omitted here for concise purpose.  
      In summary, the ink-jet printing apparatus of the invention has proper arrangements as required. Comparing with the conventional art, the invention can change the number of the ink-jet printing devise (ink-jet printing mechanism) and the positions and number of other devices (mechanisms) according to different situations. Thus, the adjustment of the apparatus has better flexibility. For example, when the throughput of the current apparatus is insufficient, the additional ink-jet print chambers (ink-jet print mechanisms) can be installed on the delivering chamber. This can increase the throughput without ordering another apparatus for larger throughput. In addition, when one ink-jet printing device is malfunction, other ink-jet print devices can keep working. Moreover, the organic material is printed in the assigned ink-jet print chamber (ink-jet print mechanism), so time for changing the material can be saved and the pollution of the different organic materials can be prevented. Furthermore, the manually moving is unnecessary in the ink-jet print processes of the invention, so not only the time cost for the manual operation can be saved, but also the organic electroluminescent panel can be prevented from the air, which results in the dark spots. Therefore, the lifetime and reliability of the panel can be assured. In addition, since ink-jet printing apparatus of the invention an automatic and integrated mass production apparatus, so that the throughput can be increased and the yield can be greatly increased.  
      Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the invention.