Abstract: A laser beam scanning system includes a light source, a projection, a micro-mirror, a controller, and a light detection module. The light source generates a laser beam, and the micro-mirror deflects the laser beam to create a scan trajectory on the projection. The controller generates a control signal and a drive signal. The control signal turns the laser beam on and off, and the drive signal controls scan movements of the micro-mirror. The light detection module is placed at a margin of the projection. The light detection module includes a photo sensor underneath a light-blocking top layer having a slot to expose the photo sensor. The photo sensor generates a detection pulse in response to detection of the laser beam in one or more segments of the scan trajectory. The controller is operative to measure a detection pulse width in clock cycles.

Abstract: A changeable structure for a faceplate of a portable computer comprises a portable computer and a cover plate; the portable computer is disposed with a housing having a faceplate; one end of the cover plate is pivotally coupled to the housing; the cover plate is disposed with a buckling element buckled up the faceplate. Whereby, the cover plate is allowed to liftably retain on the faceplate and cover a surface of the faceplate, an article is allowed to place in between the cover plate and the faceplate of the portable computer housing so as to vary an outlook or pattern of the faceplate of the computer to meet a requirement of matching the computer outlook with a personalized desire.

Abstract: A changeable structure for a faceplate of a portable computer comprises a portable computer and a cover plate; the portable computer is disposed with a housing having a faceplate; one end of the cover plate is pivotally coupled to the housing; the cover plate is disposed with a buckling element buckled up the faceplate. Whereby, the cover plate is allowed to liftably retain on the faceplate and cover a surface of the faceplate, an article is allowed to place in between the cover plate and the faceplate of the portable computer housing so as to vary an outlook or pattern of the faceplate of the computer to meet a requirement of matching the computer outlook with a personalized desire.