Abstract: It is difficult to increase consumption current of a bus-powered USB device. In order to solve this problem, a conversion cable for a DC connector and a USB connector is adopted in a USB device provided with a USB cable and a DC connector; a state in which power supply voltage is supplied to two sets of USB cables is detected; and a transistor power supply switch is turned on with a logical product thereof. An identification circuit which raises the potential of ground is incorporated in a USB conversion cable to be distinguished from an AC adaptor. When the AC adaptor is connected, the USB device operates as a self-powered USB device.

Abstract: It is difficult to increase consumption current of a bus-powered USB device. In order to solve this problem, a conversion cable for a DC connector and a USB connector is adopted in a USB device provided with a USB cable and a DC connector; a state in which power supply voltage is supplied to two sets of USB cable is detected; and a transistor power supply switch is turned on with a logical product thereof. An identification circuit which raises a potential of the ground is incorporated in a USB conversion cable to be distinguished from an AC adaptor. When the AC adaptor is connected, the USB device operates as a self-powered USB device.

Abstract: A CD-ROM drive (2) is disclosed which has a safety circuit (40). The safety circuit (40) includes a NOR gate (51) having one input connected to a disk motor drive control signal terminal (48) of a system controller (31), and another input connected to the output (P1) of a sensor (13). The system controller (31) puts out a signal that goes low for activating a motor (18) and high for inactivating the same. The motor (18) is set into rotation when the NOR gate (51) is high, and out of rotation when the NOR gate is low. When the sensor (13) is high, however, the NOR gate (51) goes low, stopping the motor (18), regardless of the other input to the NOR gate from the system controller (31).

Abstract: A disk apparatus includes a metallic chassis unit including a portion being grounded. A movable unit is provided to be movable relative to the chassis unit between an inserted position and a pulled-out position, the movable unit including an optical disk and electric parts for reproducing a signal indicative of information from the optical disk, the movable unit being included in the chassis unit when the movable unit is moved to the inserted position, and being pulled out from the chassis unit when the movable unit is moved to the pulled-out position.

Abstract: A method of operating a disk player that reproduces information recorded on a disk. Programs on the disk are addressed from a directory in a memory and the programs are sequentially accessed according to the order in the directory. The directory can be filled by inserting random numbers or by scanning through the programs or over the tracks. A table of contents at the beginning of the disk is read if possible. The tracks can be scanned and only tracks having new programs are reproduced. Also a playback position servo operates with a dead-zone in the drive voltage.

Abstract: A disc player comprising a signal pickup unit to read information from a disc on which program information including address information is recorded, the signal pickup unit being movable with respect to the disc, pickup drive means to drive the pickup unit for movement with respect to the disc, and a control circuit including an address memory for storing the newest one of the addresses read from the disc, a counter operative to count addresses at predetermined time intervals for producing a signal representative of an expected address indicative of the position to which the pickup unit is expected to move in the next, the expected address being updated at predetermined time intervals, a detector circuit to produce a signal each time a discrepancy is found to exist between the newest address and the expected address.

Abstract: An automatic disc player including a housing, disc carrier means to convey a disc between predetermined playback position and a predetermined withdrawal position ready to be withdrawn out of the housing upon termination of plaback operation, signal generating means for producing control signals to be predominant over various steps of the playback operation, and an electric control circuit responsive to the control signals to control the various steps of the playback operation, the signal generating means comprising position detecting means responsive to movement of the disc to the withdrawal position and operative to produce a signal when the disc being moved away from the playback position reaches the withdrawal position, and playback re-start switch means which is operative to produce a signal in response to slight movement of the disc from the withdrawal position toward the playback position, the control signals to be produced by the signal generating means including signals to control the start of playbac

Abstract: An automatic disc player including a housing, disc carrier means to convey a disc between predetermined playback position and a predetermined withdrawal position ready to be withdrawn out of the housing upon termination of playback operation, signal generating means for producing control signals to be predominant over various steps of the playback operation, and an electric control circuit responsive to the control signals to control the various steps of the playback operation, the signal generating means comprising position detecting means responsive to movement of the disc to the withdrawal position and operative to produce a signal when the disc being moved away from the playback position reaches the withdrawal position, and playback re-start switch means which is operative to produce a signal in response to slight movement of the disc from the withdrawal position toward the playback position, the control signals to be produced by the signal generating means including signals to control the start of playba