Abstract: An optical system affixed to an electronic apparatus is provided, including a first optical module, a second optical module, and a third optical module. The first optical module is configured to adjust the moving direction of a first light from a first moving direction to a second moving direction, wherein the first moving direction is not parallel to the second moving direction. The second optical module is configured to receive the first light moving in the second moving direction. The first light reaches the third optical module via the first optical module and the second optical module in sequence. The third optical module includes a first photoelectric converter configured to transform the first light into a first image signal.

Abstract: A direction control key assembly comprises a base on which a cover is mounted to provide an interior space for receipt of a circuit board therein which has at least four switch units thereon respectively designating a specific direction. A button member is supported on the cover by a ball joint and has four pins depending therefrom respectively corresponding to the switch units such that when the button member is rotated with respect to the ball joint to allow one of the pins to engage and thus close the corresponding one of the switch units. A direction signal associated with the closed switch is thus generated.