Electrically-operated umbrella

An electrically-operated umbrella, comprising:

• a column;
• an upper tray;
• a lower tray;
• a plurality of long rods, each having a middle portion and an upper portion, each rotatably connected to the upper tray;
• a plurality of short rods having two ends;
• and
• an electric air pump;
• wherein,
• one end of each short rod is rotatably connected to the lower tray, the other end of each short rod is rotatably connected to the middle portion or the upper portion of the corresponding long rod;
• the column comprises an inner tube having a top and a bottom, and an outer tube having a top, a bottom and a lower portion, the outer tube is sleeved around the inner tube, the inner tube is capable of sliding up and down relative to the outer tube in a limited range of motion;
• a closed air chamber is defined between the bottom of the inner tube and the bottom or the lower portion of the outer tube;
• the upper tray is connected to the top of the inner tube, the lower tray is connected to the outer tube and sleeved around the outer tube;
• the electric air pump is disposed inside the inner tube to inflate or deflate the air chamber so as to drive the inner tube to slide up and down;
• and the upper tray is capable of sliding up and down with the inner tube relative to the outer tube and the lower tray, so as to drive the plurality of long rods and the plurality of short rods to rotate in order to fold or unfold the umbrella.