Patent Publication Number: US-10780468-B2

Title: Cleaning device and cleaning method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority to Chinese Patent Application No. 201710708404.X, filed on Aug. 17, 2017, the contents of which are incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to the display field, in particular to a cleaning device for cleaning the electronics and the cleaning method corresponding to the cleaning device. 
     BACKGROUND 
     In the display panel manufacturing industry, especially the liquid crystal panel manufacturing industry, it is usually necessary to clean the display cell to remove the foreign matter on the surface of the display cell before attaching the polarizing film (POL) on the display cell which has been cut. 
     At present, the cleaning devices in related art usually uses normal-temperature water, i.e., cold water, to wash the display cell, and then wipes and cleans the display cell by using abrasive belt, abrasive pad (PAD) or abrasive cloth to clean the display cell, so as to clean the display cell. The risk that residual adhesive may remain at the display cell exists in all the pre-process sections such as process of preparing the array substrate, pasting the color film, manufacturing the display cell and the like, and the residual adhesive and feculence-like foreign matter adhering to the surface of the display cell will cause the product&#39;s yield to decline after adhering the polarizing film to the display cell. According to the data statistics, 20% of the defective display panel due to bubble type is caused by the residual adhesive at the display cell. 
     The cleaning process in related art mainly exists the following defects: 
     On the one hand, the cleaning device in related art generally uses normal temperature water, i.e., cold water, to clean, which generally difficult to completely remove the feculence, in particular the cured organic oil, from the surface of the display cell. 
     On the other hand, the cleaning device in related art may easily cause the display device to be damaged due to larger local stress, and may even cause the display cell to be damaged. 
     The information as above disclosed in the background is merely employed to enhance understanding of background of this disclosure. 
     SUMMARY 
     According to one aspect of this disclosure, providing a cleaning device which comprises sweeping module and washing module. The sweeping module includes a brush component and a steam generating component, the steam generating component and the brush component are arranged in sequence in the cleaning direction of the cleaning device; the washing module is configured to wash the parts to be cleaned, the washing module and the sweeping module are arranged in sequence in the cleaning direction of the cleaning device. 
     According to an embodiment of the disclosure, the brush component comprises a brush, an actuator, a pressure sensor and a controller, a cleaning face of the brush is disposed towards and parallel to the part to be cleaned; the actuator is configured to drive the brush to move; the pressure sensor is configured to measure a pressure of the cleaning face of the brush, and transmit a pressure signal to the controller; the controller is electrically connected to the actuator and the pressure sensor respectively; the controller is configured to receive the pressure signal from the pressure sensor, and generate a control signal according to the pressure signal for transmitting to the actuator. 
     According to an embodiment of the disclosure, the brush is a plate-type brush which comprises a plate body part and a brush part, the plate part has a first surface which is parallel to the cleaning face, the brush part is disposed on the first surface, and a extend direction of a brushing of the brush part is perpendicular to the first surface; the plate body part is connected with the actuator. 
     According to an embodiment of the disclosure, the steam generating component comprises a steam generator and a steam ejector, a steam generated by the steam generator is sprayed by the steam ejector to a surface to be cleaned of the part to be cleaned. 
     According to an embodiment of the disclosure, a temperature of the steam is greater than 90° C. 
     According to an embodiment of the disclosure, the cleaning device further comprises a cleaning fluid supply module which comprises a liquid vessel and a pipeline, the pipeline is communicated with the sweeping module and the washing module respectively. 
     According to an embodiment of the disclosure, in a direction of movement of the part to be cleaned, the washing module comprises a first cleaning portion, a second cleaning portion and a final cleaning portion arranged in sequence, the liquid vessel comprises a first liquid vessel and a second liquid vessel separated from each other, a liquid outlet of the first liquid vessel is communicated with the final cleaning portion, a liquid outlet of the second liquid vessel is communicated with the first cleaning portion and the second cleaning portion respectively, the liquid outlet of the first cleaning portion, the liquid outlet of the second cleaning portion and a liquid outlet of the final cleaning portion are communicated with a liquid return port of the second liquid vessel respectively. 
     According to an embodiment of the disclosure, the cleaning fluid supply module further comprises a heating device, which is configured to heat the cleaning fluid and disposed on the pipeline, and/or in the liquid vessel. 
     According to an embodiment of the disclosure, a temperature of the cleaning fluid after being heated by the heating device is about 40° C. to 50° C. 
     According to an embodiment of the disclosure, the cleaning device further comprises a camera device, an air knife unit and an optical detection device, the camera device, the sweeping module, the washing module, the air knife unit and the optical detection device are sequentially arranged in the cleaning direction in sequence. 
     According to another aspect of this disclosure, providing a cleaning method, wherein the cleaning method uses the cleaning device according to claim  1  for cleaning, the cleaning method comprises the following steps:
         generating steam by the steam generating component to act on the part to be cleaned;   sweeping one surface of the part to be cleaned by the brush component;   after the one surface is swept, then sweeping the other surface, which is opposite to the one surface; and   washing the part to be cleaned after being swept with the washing module.       

     According to an embodiment of the disclosure, the steam generating component comprises a steam generator and a steam ejector, the step of generating steam by the steam generating component to act on the part to be cleaned comprises:
         heating cleaning fluid from liquid into steam by the steam generator, and spraying the steam on the part to be cleaned by the steam ejector.       

     According to an embodiment of the disclosure, the cleaning device further comprises a cleaning fluid supply module which is configured to transport cleaning fluid to the sweeping module and the washing module, the cleaning fluid module comprises a heating device, before the step of washing the part to be cleaned after being swept with the washing module, heating the cleaning fluid by the heating device. 
     According to an embodiment of the disclosure, the part to be cleaned is a display panel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects, features and advantages of the present disclosure will become more apparent from the following detailed description thereof when taken in conjunction with the accompanying drawings. The companying drawings are merely illustrative but not necessarily to scale. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Wherein: 
         FIG. 1  is a flow chart of a cleaning device according to an embodiment. 
         FIG. 2  is a schematic diagram of the working principle of an abrasive belt in  FIG. 1 . 
         FIG. 3  is a block diagram of a cleaning device according to another embodiment. 
         FIG. 4  is a flow chart of a cleaning device according to another embodiment. 
         FIG. 5  is a flow chart of a sweeping module and washing module in  FIG. 4 . 
         FIG. 6  is a flow chart of a cleaning fluid supply module in  FIG. 4 . 
         FIG. 7  is a block diagram of a brush component in  FIG. 3 . 
         FIG. 8  is a schematic structural view of the brush component in  FIG. 3 . 
         FIG. 9  is a schematic structural view of a cleaning face of a brush in  FIG. 8 . 
         FIG. 10  is a water temperature-solubility curve. 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary implementations will now be described sufficiently with reference to the accompanying drawings. However, the exemplary implementations can be carried out in variety of forms, but should not be construed as limiting the embodiments set forth herein. Rather, these implementations are provided such that this disclosure will be thorough and complete, and will transmit concepts of the exemplary implementations completely to those skilled in the art. The same reference numbers in the drawings serve to denote the same or similar structures, and accordingly their detailed descriptions will be omitted. 
     The cleaning device provided by the present disclosure is suitable for a display panel and can also be applied to other electronic components, and is within the protection scope of the present disclosure. In order to describe the present disclosure more clearly, the present disclosure uses a display panel as the part to be cleaned as an example. Upstream and downstream defined in the present disclosure are defined according to the direction of movement of the display panel, the display panel moves from upstream to downstream, the direction of movement from upstream to downstream can be defined as a cleaning direction, that is, the direction of movement of the display panel can be defined as the cleaning direction. 
     An embodiment of the present disclosure provides a cleaning device, as shown in  FIG. 1 , the cleaning device wipes the surface of the display cell with cleaning tools such as a nylon roller brush  1 , an abrasive belt  2  and the like, the abrasive belt  2  is usually used to just rub against residual adhesive, which usually thins the thickness of the residual adhesive, while largens the area of the residual adhesive, therefore, not only does it not remove the residual adhesive, it increases the amount of clean work; in addition, since the contact surface of the roller brush  1  and the display panel  3  is usually the outer peripheral surface of the roller brush, almost linear contact between the two, which easily causes damage to the display device due to larger local stress. 
     On another aspect, in order to meet the market demand, the current display unit tends to a development of thin type, as shown in  FIG. 2 , the cleaning device of the present embodiments is provided with two abrasive belts  2  on the two opposite sides of the display cell  3 , the two abrasive belts  2  respectively rotate under the drive of the respective driving rollers  4 , the two abrasive belts  2  produce friction in two opposite directions to the display cell, that is to say, in the cleaning process for the display cell by the abrasive belts  2 , a side of display cell where the thin film transistor (TFT) is disposed and a side of display cell where the color film (CF) need to be subjected to friction cleaning at the same time, so that the display cell receives the opposite force at the same time, which affects the structural strength of the display cell, even causes damage to the display cell. 
     Refer to  FIG. 3  to  FIG. 5 , according to an aspect of the present disclosure, there is provided a cleaning device which may include a sweeping module  100  and a washing module  200 . The sweeping module  100  includes a brush component  7  and a steam generating component  19 , the steam generating component and the brush component  7  are sequentially arranged in the cleaning direction of the cleaning device. The washing module  200  is used to wash a part to be cleaned, and the washing module  200  and the sweeping module  100  are sequentially disposed in the cleaning direction of the cleaning device. 
     The cleaning device may include a camera device  15 , a sweeping module  100 , a washing module  200 , an air knife unit  18  and an optical detection device  17  which are sequentially arranged in the cleaning direction of the cleaning device, specific description please refer to the following description. The direction of arrow in  FIG. 4  is the flow direction of the cleaning fluid. With continued reference to  FIG. 4  and  FIG. 5 , according to a specific embodiment of the disclosure, wherein the sweeping module  100  may be located at upstream of the cleaning device, the steam generating component  19  may be located at upstream of the brush component  7 . In the process of cleaning the display panel  3 , the display panel  3  may first pass through the steam generating component  19  which may generate hot steam acting on the surface of the display panel  3 . In the present disclosure, steam is generated by the steam generating component  19  and applied to the surface of the display panel  3  to be cleaned, thus the dirt remaining on the surface of the display panel  3 , for example but not limited to residual gel, can be soaked and softened. The display panel  3  of which the dirt on the surface has been softened is further cleaned by the brush component  7 , so that the cleaning efficiency would be improved. 
     With continued reference to  FIG. 4  and  FIG. 5 , according to a specific embodiment of the disclosure, wherein the steam generating component  19  may include a steam generator  5  and a steam ejector  6 , the steam generator  5  can be used to generate steam which can be sprayed onto the surface to be cleaned of the display panel  3  via the steam ejector  6 , but not limited thereto. According to one specific implementation of the present disclosure, wherein the cleaning fluid may be clean water, it can also be a cleaning solution formed by adding some kinds of organic solvent to clean water, all of which are contained within the protection scope of the disclosure, those skilled in the art can choose according to actual needs. Since the cleaning fluid is not an important disclosure point of the present disclosure, it will not be repeated here, the dirt may be, for example but not limited to, an original condensate, oil thereof can be decomposed, softened and dissolved with the help of the steam. Refer to  FIG. 10 , in case that clear water is used as a cleaning fluid, wherein it can be understood that the higher the temperature of the clear water, the greater its solubility. In addition, also refer to table  1 , as the water temperature of the clean water rises, the surface tension of the clean water will decrease, so that its viscosity decreases, thusly improving the ability of soak. According to the actual needs, the steam temperature can be adjusted, for example but not limited to an embodiment according to the present disclosure, wherein the temperature of the steam can be greater than 90° C., for example but not limited to a steam temperature may be 100° C., or 150° C., or 200° C., or 250° C., or 300° C., all of which are contained within the protection scope of the disclosure, those skilled in the art can choose the steam temperature according to actual needs. The steam could swell, soak and dissociate the residual adhesive on the surface of the display panel  3 , compared with the solubility of organic substances in normal temperature water, the solubility of organic substances in the high-temperature steam is higher, thusly having a better cleaning effect. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 The data graph showing water surface tension is 
               
               
                 affected by temperature 
               
            
           
           
               
               
            
               
                   
                 Temperature (° C.) 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 0 
                 20 
                 40 
                 60 
                 80 
                 100 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Surface tension (dyne/cm) 
                 75.64 
                 72.75 
                 69.59 
                 66.18 
                 62.61 
                 58.85 
               
               
                   
               
            
           
         
       
     
     Refer to  FIG. 3 , according to a specific embodiment of the disclosure, the cleaning device may also include a cleaning fluid supply module  300  which may include a liquid vessel  310  and a pipeline  320 , the pipeline  320  may be connected to the sweeping module  100  and washing module  200  respectively, to transfer the cleaning fluid within the liquid vessel  310  to the sweeping module  100  and the washing module  200 . 
     With continued reference to  FIG. 3  to  FIG. 5 , according to a specific embodiment of the disclosure, in the cleaning direction, the sweeping module  100  and the washing module  200  may be sequentially disposed, the sweeping module  100  first cleans the display panel  3 , then the washing module  200  washes it with a cleaning fluid, to separate the dirt from the display panel  3 . According to an specific embodiment of the disclosure, wherein in the direction of movement of the display panel, the washing module  200  may include a first cleaning portion  8 , a second cleaning portion  9  and a final cleaning portion  10  arranged in sequence in the cleaning direction, the liquid vessel  310  may include a first liquid vessel  12  and a second liquid vessel  11  separated from each other, the liquid outlet of the first liquid vessel  12  may be communicated with the final cleaning portion  10 , the liquid outlet of the second liquid vessel  11  may be communicated with the first cleaning portion  8  and the second cleaning portion  9  respectively, the liquid outlet of the first cleaning portion  8 , the liquid outlet of the second cleaning portion  9  and the liquid outlet of the final cleaning portion  10  are communicated with the liquid return ports of the second liquid vessel  11  respectively. According to an specific embodiment of the disclosure, the liquid vessel  310  may also include a third liquid vessel  16  which can be communicated with the second liquid vessel  11 , the third liquid vessel  16  can be used to collect waste liquid discharged from the first cleaning portion  8 , the second cleaning portion  9  and the final cleaning portion  10 , The waste liquid can be purified by the sewage purification device  14  and then return to the second liquid vessel  11  again, to participate in the cleaning process for the next display panel  3 . By means of the third liquid vessel  16 , the sewage purification device  14 , and the second liquid vessel  11  communicated successively, it can be more environmentally friendly. With continued reference to  FIG. 6 , the cleaning fluid in the second liquid vessel  11  is passed into the steam generator  5  to generate steam to act on the surface to be cleaned of the display panel  3 , the liquid cleaning fluid produced in this process will be directly discharged from the cleaning device. The direction of the arrow in  FIG. 6  is the flow direction of the cleaning fluid. 
     With continued reference to  FIG. 7  to  FIG. 9 , according to a specific embodiment of the disclosure, the brush component  7  may include a brush  72 , an actuator  71 , a pressure sensor  73  and a controller  74 . The cleaning face of the brush may be disposed towards the display panel  3 , and parallel to the display panel  3 . The actuator  71  can drive the brush  72  to move, for example but not limited to drive the brush  72  to move on the surface to be cleaned of the display panel  3  to sweep the surface to be cleaned; the actuator  71  may also drive the brush  72  to move in the direction perpendicular to the surface to be cleaned of the display panel  3  to be close to or away from the display panel  3 , thus the pressure of the cleaning face of the brush  72  can be adjusted. The pressure sensor  73  may be used to measure the pressure of the cleaning face of the brush  72 , and transmit the measured pressure signal to the controller  74 . The controller  74  is electrically connected to the actuator  71  and the pressure sensor  73  respectively, receives the pressure signal measured by the pressure sensor  73 , and generates a control signal according to the pressure information for transmitting to the actuator  71 . 
     The pressure sensor  73  can measure the stress acting on the display panel  3  in real time, thereby preventing damage to the display panel  3  due to excessive stress from the brush  72 , in addition, avoiding incomplete clean due to insufficient stress between the brush  72  and the display panel  3 . Further, in case of a worn brush  72 , by the cooperation of the controller  74 , the pressure sensor  73  and the brush  72 , the stress between the brush  72  and the display panel  73  can be maintained constant. According to a specific embodiment of the disclosure, the pressure sensor  73  and/or the controller  74  can be integrated inside the brush  72 , it can also be formed outside of the brush  72 , all of which are contained within the protection scope of the present disclosure. 
     With continued reference to  FIG. 8  and  FIG. 9 , according to a specific embodiment of the disclosure, wherein the brush  72  may be a plate-type brush which may include a plate body part  721  and a brush part  722 . The plate body part  721  may have a first surface S 1 , the first surface S 1  may be parallel to the cleaning face. The brush part  722  may be disposed on the first surface, and the extend direction of the brushing of the bush part  722  may be perpendicular to the first surface S 1 . The plate body part  721  may be connected with the actuator  71  to support the brush part  722 . According to a specific embodiment of the disclosure, wherein a water outlet hole  723  may be further provided on the first surface S 1  of the plate body part  721 , the water outlet hole  723  can be communicated with the liquid vessel  310  through the pipeline  320 , such that the display panel  3  could be swept while washed by the brush component  7 , thusly improving the cleaning efficiency. The brush  72  provided by the present disclosure is a plate-type brush, which could avoid the problem of line contact between a roller-type brush and the display panel  3 , thusly avoiding the problem of local stress concentration of the display panel  3  to a certain degree. 
     According to a specific embodiment of the disclosure, wherein the cleaning fluid supply module  300  may also include a heating device  13  which heats the cleaning fluid. The heating device  13  is disposed on the pipeline  320 , and/or the heating device  13  is disposed in the liquid vessel  310 . According to a specific embodiment of the disclosure, wherein the cleaning fluid may be heated to a temperature about 40° C. to 50° C. by the heating device  3  with error of 5° C., for example, is 35° C., 39° C., 41° C., 51° C., 55° C. The cleaning fluid heated by the heating device  13  can be passed into the steam generator  5 ; in addition, the cleaning fluid heated by the heating device  13  can also be passed into the brush  72 , such that the display panel  3  could be swept while washed, thusly improving the cleaning efficiency; in addition, the cleaning fluid heated by the heating device  13  can also be passed into the washing module  200 , thusly further improving washing efficiency. Specifically, the cleaning fluid heated by the heating device  13  can prevent re-solidification of the organic grease such as residual adhesive that has been soaked by steam, so that the washing efficiency can be improved. 
     According to a specific embodiment of the disclosure, a cleaning method is provided, which uses above mentioned cleaning device for cleaning, wherein the cleaning method includes the following steps: a steam generating component  19  generates steam to act on the surface to be cleaned of display panel  3 , the steam can fully soak the organic grease such as residual adhesive on the display panel  3  so as to prepare for the subsequent sweeping and washing processes. The brush component  7  can first sweep one surface of the display panel  3 ; After the one surface, for example but not limited to a surface of the color film, is swept, then sweep the other surface, which may be a surface of the thin film transistor, and the one surface and the other surface may be oppositely disposed. Then washing the cleaned display panel  3  by using the washing module  200 . In the cleaning method of the display panel provided by the present disclosure, different surfaces to be cleaned of the display panel  3  are cleaned respectively, such that it is possible to avoid opposing forces acting on the opposite surfaces of the display panel  3  at the same time, thusly avoiding the problem that the strength of the display panel itself is impaired. According to a specific embodiment of the disclosure, the heating device  13  can be used to heat the cleaning fluid before the washing module  200  performs the washing step to the display panel  3 . 
     The steam generating component  19  of the cleaning device of the present disclosure may include a steam generator  5  and a steam ejector  6 . The steam generator  5  can heats cleaning fluid from liquid into steam, then the steam ejector  6  can spray the steam on the surface of the display panel  3  to be cleaned to soak and soften organic grease such as residual adhesive, so as to prepare for subsequent cleaning and washing. The cleaning device may also include cleaning fluid supply module  300 , the cleaning fluid supply module  300  is configured to transport the cleaning fluid to the sweeping module  100  and the washing module  200 . The cleaning fluid supply module  300  may include a heating device  13 , which is used to heat the cleaning fluid so as to perform clean process subsequently. Therefore, it is possible to prevent the organic grease, which has been soaked and softened, from being re-solidified, thereby improving the cleaning efficiency. 
     Based on the above technical solutions, it can be seen that the advantages and positive effects of the cleaning device and cleaning method of the present disclosure are as follows: Steam is generated by the steam generating component and applied to the surface of the parts to be cleaned, so that dirt, for example but not limited to, residual adhesive, remaining on the surface of the parts to be cleaned can be soaked and softened, so that the brush component can clean it, thusly improving cleaning efficiency. 
     The features, structures, or properties described herein may be incorporated into one or more implementations in any suitable manner. In the above description, numerous specific details are provided to provide a thorough understanding of embodiments of the present disclosure. However, those skilled in the art will realize that the aspects of the disclosure may be practiced without one or more specific details or by means of other methods, components and materials, etc. Under the other circumstances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring variable aspects of the disclosure.