The present invention relates to a direction control mechanism of an endoscope, comprising a steering wheel and a brake assembly, wherein the brake assembly has a brake pedestal, a control pedestal, and at least two steel balls, the brake pedestal has at least two steel-ball fixing holes, the control pedestal has at least two positioning grooves, the distance between one end of each positioning groove and the brake pedestal is greater than the distance between the other end of each positioning groove and the brake pedestal, each steel ball is disposed between the steel-ball fixing hole of brake pedestal and the positioning groove of the control pedestal. In this way, when the control pedestal is at a release position, the control pedestal will not abuttingly push the brake pedestal, so that the steering wheel is allowed to rotate without being subjected to the braking action of the brake pedestal. When the control pedestal is at a brake position, the control pedestal will abuttingly push each steel ball through the groove surface of each positioning groove, so that the control pedestal will tightly press against the steering wheel to disallow the steering wheel to rotate.本發明有關於一種內視鏡之方向控制機構,包含有一方向轉盤及一制動組件,其中的制動組件具有一制動座、一控制座,以及至少二鋼珠,制動座具有至少二鋼珠固定孔,控制座具有至少二定位槽,各定位槽之一端至制動座之距離大於各定位槽之另一端至制動座之距離,各鋼珠設於制動座之鋼珠固定孔及控制座之定位槽之間,藉此,當控制座位於一釋放位置時,控制座不會推頂制動座,使得方向轉盤不會受到制動座之煞車作用而能轉動,當控制座位於一制動位置時,控制座會藉由各定位槽之槽面推頂各鋼珠,使得制動座會迫緊方向轉盤而讓方向轉盤無法轉動。10‧‧‧方向控制機構20‧‧‧轉軸22‧‧‧軸桿24‧‧‧轉輪26‧‧‧固定環30‧‧‧方向轉盤40‧‧‧制動組件41‧‧‧軸套412‧‧‧軸部42‧‧‧制動座43‧‧‧鋼珠44‧‧‧控制座45‧‧‧座體452‧‧‧鋼珠固定孔454‧‧‧矩形套孔46‧‧‧制動片47‧‧‧轉盤472‧‧‧圓形套孔48‧‧‧操控桿49‧‧‧定位槽492‧‧‧槽面494‧‧‧第一端496‧‧‧第二端
