Abstract: An optical system is provided. The optical system is used for disposing on an electronic device. The optical system includes a movable portion, a fixed portion, a first driving assembly, and a support module. The movable portion is used for connecting to an optical module. The fixed portion is affixed on the electronic device, and the movable portion is movable relative to the fixed portion. The first driving assembly is used for driving the movable portion to move relative to the fixed portion. The movable portion is movably connected to the fixed portion through the support module.

Abstract: A wind guiding cover, mounted on a fan, includes a rotating ring and a plurality of slats. The rotating ring is pivoted to the fan, and has an opening for an air flow generated by the fan to pass through. The rotating ring has a weight portion for offsetting the center of gravity of the rotating ring and normally maintaining the rotating ring at a static equilibrium position. The slats are pivoted to the rotating ring and arranged at the opening. When the fan operates, the slats are lifted by the air flow to open the opening. When the fan stops operating, the slats cover the opening under the gravity.

Abstract: A wind guiding cover, mounted on a fan, includes a rotating ring and a plurality of slats. The rotating ring is pivoted to the fan, and has an opening for an air flow generated by the fan to pass through. The rotating ring has a weight portion for offsetting the center of gravity of the rotating ring and normally maintaining the rotating ring at a static equilibrium position. The slats are pivoted to the rotating ring and arranged at the opening. When the fan operates, the slats are lifted by the air flow to open the opening. When the fan stops operating, the slats cover the opening under the gravity.

Abstract: A computer host having two layers inside includes a chassis, a partition, a first circuit board, a second circuit board, and an electrical connecting device. The partition divides the interior of the chassis into a first accommodation space and a second accommodation space. The first circuit board and the second circuit board are disposed on two sides of the partition respectively, and are respectively located in the first accommodation space and the second accommodation space. The electrical connecting device is used to electrically connect the first circuit board and the second circuit board, so that the first and second circuit boards together form a complete electronic circuit system for the operation of the computer host.