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 portable electronic device is provided. The portable electronic device includes a casing, a display unit, a roller, an encoder and a controller. The casing has a casing surface. The display unit is disposed on the casing surface. The roller is rotatably disposed on the casing surface with a portion of the roller being exposed outside the casing. The roller is for adjusting the voice of the portable electronic device when the portable electronic device works at a voice-adjusting mode. The roller is for touching a surface and rotating on the surface to measure a length when the portable electronic device works at a length-measuring mode. The encoder disposed inside the casing is for outputting a pulse number. The controller receives the pulse number and determines a length value accordingly, and then controls the display unit to display the length value.

Abstract: A portable electronic device is provided. The portable electronic device includes a casing, a display unit, a roller, an encoder and a controller. The casing has a casing surface. The display unit is disposed on the casing surface. The roller is rotatably disposed on the casing surface with a portion of the roller being exposed outside the casing. The roller is for adjusting the voice of the portable electronic device when the portable electronic device works at a voice-adjusting mode. The roller is for touching a surface and rotating on the surface to measure a length when the portable electronic device works at a length-measuring mode. The encoder disposed inside the casing is for outputting a pulse number. The controller receives the pulse number and determines a length value accordingly, and then controls the display unit to display the length value.