A continuous cell air-extracting technique (CCAE) has been successfully applied for cell filling of flexible liquid-crystal displays. This CCAE technique can conduct cell filling of liquid crystals in an atmospheric ambient and keep cell pressure constant during the entire cell-filling period. Cell-filling efficiency was found to be dependent on cell pressure, spacer-area density, and injection-port width at room temperature. A filling time of 141 s was achieved for a polyethylene-terephthalate substrate with a 67 x 55 mm(2) cell at a constant cell pressure of 2 torr, which is faster than the traditional method by at least a factor of 2. The enhanced cell-filling efficiency is mainly attributed to the fact that the flow speed of liquid crystal is not largely reduced in the cell because of the constant cell pressure. The cell-filling efficiency was, however, found to be limited by cell-deformation-caused cell resistance. (C) 2010 American Vacuum Society. [DOI: 10.1116/1.3437008]