Abstract: An optical communication interface module includes a combined transmission module and a combined reception module. The combined transmission module processes a D+ electrical data signal and a D? electrical data signal, and combines and transmits the same through a first optical fiber line. The combined reception module processes the D+ and D? electrical data signals combined and received through a second optical fiber line, and applies the D+ and D? electrical data signals to a D+ port and D? port, respectively. The combined transmission module includes a transmission driving circuit that generates an optical data signal corresponding to one of the D+ and D? electrical data signals, and a transmission control switch that controls the optical data signal to have a level of brightness higher than a first set value while the D+ and D? electrical data signals are both maintained at a logic ‘low’ state, and controls the transmission driving circuit.

Abstract: An optical communication interface module includes a combined transmission module and a combined reception module. The combined transmission module processes a D+ electrical data signal supplied from a D+ port of a universal serial bus (USB) and a D− electrical data signal supplied from a D− port, and combines and transmits the same through a first optical fiber line. The combined reception module processes the D+ and D− electrical data signal combined and received through a second optical fiber line and applying the D+ and D− electrical data signals to the D+ port and the D− port, respectively. Here, the combined transmission module includes a transmission driving circuit and a transmission control switch. The transmission driving circuit generates an optical data signal corresponding to one of the D+ and D− electrical data signals supplied from the D+ and D− ports of the USB, to be applied to the first optical fiber line.

Abstract: A spindle motor driver is provided. The spindle motor driver includes a spindle motor for rotating an optical disc, an optical head for reading signals from the optical disc to reproduce the information recorded on the optical disc, a processor for processing the detected signals, and a constant linear velocity (CLV) servo for controlling the spindle motor to rotate with a CLV according to the signal processed by the processor. A constant angular velocity (CAV) servo is connected in parallel to the CLV servo to control the spindle motor to rotate with a CAV when the optical head performs jumping. Additionally, a feedback loop is provided between the spindle motor and the CAV servo for feeding back the rotation speed signal of the optical disc. A switching means selectively connects the processor with the CAV servo and the CLV servo. Thus, access time of the optical head can be effectively shortened.