How long after their discovery did it take the scientific community to accept the existence of cells?

It hadn't taken too much time as the work of Robert Hooke was continued by other scientists after his death. Robert Hooke described the cell and gave it its name in 1665. Scientists like Antonie van Leeuwenhoek (1670), Robert Brown (1833), Schleiden (1838) and Schwann (1839) completed the work of Robert Hooke. The cell theory that gathered the work of all these scientists was suggested by Schleiden and Schwann in 1839.