The construction of a folding device is complicated and its failure probability is high. Through the use of the apparatus, a video teleconference environment can communicate, in real time, such personal features as gesture, expression and body language. In some embodiments, the processing circuit controls a suspension system and can control the suspension system to have any of a multiplicity of height settings. These water droplets or oil droplets fall and flow to the inner wall surface of the upper wall of the casing along the inner peripheral wall of a vent hole. Retaining pins with enlarged heads engage the wafer edge and prevent it from being displaced upwardly when a high flow rate of gas is utilized.