Abstract: Mobile networks may be configured to broadcast wireless emergency alert (WEA) messages to receiving mobile devices. A mobile device within the network may receive a WEA message including data defining a geographic region associated with the message. Using the data defining the geographic region for the WEA message, the mobile device may perform location-based geofencing techniques to determine whether to present a notification in response to the WEA message. In various examples, a mobile device may calculate an offset distance based on a transgression parameter and may determine a second geographic region using the offset distance. The mobile device also may determine its current location and compare the location to the second geographic region to determine whether to present the WEA message, thereby limiting and/or minimizing the negative effects of potential undershoot and overshoot errors caused by inaccurate location determinations by mobile devices.

Abstract: A wobble determining apparatus is provided with: a calculating device for calculating (i) a first time required until reaching a number of revolutions of a motor which allows a predetermined linear velocity, and (ii) a second time required to move an optical head to a position which allows the predetermined linear velocity, on the basis of the number of revolutions of the motor and the position of the optical head; a judging device for judging whether to keep the optical head in accordance with the calculated first time and the calculated second time; and a controlling device for controlling a moving device not to move the optical head if it is judged to keep the optical head, and for controlling the moving device to move the optical head to the position which allows the predetermined linear velocity if it is judged not to keep the optical head.

Abstract: A wobble determining apparatus is provided with: a calculating device for calculating (i) a first time required until reaching a number of revolutions of a motor which allows a predetermined linear velocity, and (ii) a second time required to move an optical head to a position which allows the predetermined linear velocity, on the basis of the number of revolutions of the motor and the position of the optical head; a judging device for judging whether to keep the optical head in accordance with the calculated first time and the calculated second time; and a controlling device for controlling a moving device not to move the optical head if it is judged to keep the optical head, and for controlling the moving device to move the optical head to the position which allows the predetermined linear velocity if it is judged not to keep the optical head.

Abstract: An optical disc device includes a pickup, a driving mechanism that drives the pickup, and a driving controlling portion that applies an initial driving voltage to the driving mechanism over a specific time interval up until the pickup arrives at an outermost position on an outer peripheral side, the initial driving voltage causing the pickup to arrive at the outermost position. After the specific time interval has elapsed, the driving controlling portion applies, to the driving mechanism, an adjustment driving voltage of a voltage amplitude less than a voltage amplitude of the initial driving voltage or a driving frequency less than a driving frequency of the initial driving voltage.

Abstract: As imaging devices are miniaturized, and optical devices are miniaturized, lens moving mechanisms are also miniaturized. Thus, position sensors for them are required to be miniaturized and have high accuracy at low cost. A magnet of a pillar shape and a yoke which move in the X axis direction with respect to a magnetic field detection element are provided, and a shape of a cross section of the yoke which is orthogonal to a longitudinal direction of the magnet changes along the longitudinal direction.

Abstract: An optical pickup assembly that has flexible beams that support an objective lens for adjustment in a focusing direction and a tracking direction. The flexible beams are used to support and move the objective lens. A controller operates electromagnetic actuators that move the flexible beams.

Abstract: A disk drive for driving a disk is disclosed, which includes: a driving unit configured to provide a driving force onto the disk, a main circuit pattern electrically connected with the driving unit, a sensor unit configured to sense a rotation speed of the disk, a first board supporting the sensor unit, a second board supporting the first board, and a base plate supporting the second board and the driving unit. One of the first board and the second board can be a flexible board electrically connecting the sensor unit with the main circuit pattern, and the other of the first board and the second board can be a rigid board. This disk drive can be utilized to ensure the distance between the sensor unit and the disk required for a rotation sensor to measure the rotation speed of the disk.

Abstract: Provided is a low-cost, high-accuracy optical pickup supporting device by simplifying a structure for fixing guide shafts to a chassis. To this end, an optical pickup supporting device includes: a frame-shaped chassis; a first guide shaft and a second guide shaft, two ends of each of which are fixed to the chassis; an optical pickup device movably supported by the two guide shafts; and a spindle motor fixed to the chassis with a motor supporting member interposed in between. Furthermore, in a first fixation region in which the first guide shaft is fixed to the chassis, the position of the first guide shaft is fixed with higher accuracy by: a fixation area obtained by protruding parts of the chassis; and a position regulating portion which is a part of the motor supporting member.

Abstract: This invention relates to a wire-free sensing apparatus used in a disc system. The apparatus mainly comprises a beam emitting source installed at the case for emitting a beam, a reflector installed at the drawer for reflecting the beam, a beam receiving end installed at the case for receiving the beam reflected by the reflector, a switch installed at the drawer for controlling whether the reflector reflects the beam or not, and a one-way mirror installed at the case. The one-way mirror forms a non-right angle with an emitting direction of the beam and has a penetrating surface and a reflecting surface at opposite sides thereof wherein the beam penetrates the penetrating surface, and can be reflected by the reflector to the reflecting surface and then reflected by the reflecting surface to the beam receiving end.

Abstract: The present invention is directed to an optical disk reproducing device including an external optical disk drive and a detachable module. The external optical disk drive reproduces data from the optical disk. The detachable module has an audio output or video output connector. Besides, the external optical disk drive has a first connector and the detachable module has a corresponding second connector. The detachable module is connected with an audio output device or a video output device via the audio output connector or the video output connector respectively. After data is processed in the external disk drive, the data is sent to the control chip for further processing. The data processed by the control chip is sent to the audio output device or the video output device.

Abstract: An angle sensor includes a rotary disc provided with an annular surface divided into cells for encoding the angular position of the disc, the said cells transforming an incident light beam into an optical light signal conveying a code of the said angular position, the said signal being conducted by a light guide to a fixed photodetector connected to means for processing of the said code. The light guide is moveable in rotation about an axis parallel with the axis of rotation of the disc, an arm attached to the said guide, driven in a radial direction by the rotating disc, displacing the light guide relatively to the photodetector.

Abstract: A method is used for detecting a tilt of an optical pickup head. The method includes the steps of: capturing a plurality of images; converting the images to bitmap images; superposing the bitmap images together to form an superimposed bitmap image; setting a two-dimensional coordinating system of the superimposed bitmap image; determining coordinates of a first static spot, a second static spot, and dynamic spot; calculating a first distance between the first static spot and the dynamic spot, and a second distance between the second static spot and the dynamic spot based on the coordinates to determine a maximum distance; and comparing the maximum distance with a first standard distance to attain a conclusion whether the tilt is in an acceptable range.

Abstract: The whole reflection signal and a tracking error signal are detected while an objective lens is being moved in the radial direction of an optical disk, and the temporal difference between a time at which the value of the whole reflection signal becomes a maximum and a time at which the value of the tracking error signal becomes zero is detected in a predetermined time period. In addition, a value which is obtained by dividing the temporal difference by the time period of one cycle of the tracking error signal is acquired as a tilt appearance magnitude. Relational information in which a tilt appearance magnitude and a tilt correction magnitude corresponding to the tilt appearance magnitude are associated is read out, and the relational information read out and the current tilt appearance magnitude detected by a tilt-appearance-magnitude detection circuit are compared, thereby to determine the tilt correction magnitude necessary for a tilt correction.

Abstract: An optical pickup unit (OPU) includes a moveable structure that is moved by a voice coil motor component in response to an input signal. The moveable structure includes a pattern that is moved corresponding to the input signal. An encoder reads the pattern to generate an output signal that corresponds to pattern movement as the input signal is applied over a period of time. A controller calculates a calibration factor relating the pattern movement to the input signal.

Abstract: An information recording and/or reading apparatus has a base plate, a spindle motor for rotating a disk by the output shaft perpendicular to the base plate, a rotary alignment control device for determining the rotation position of a recording/reading head of a head unit about a rotary alignment axis parallel to the output shaft of the spindle motor, a linear movement guide extending parallel to the rotary alignment axis, and a support mechanism for supporting the rotary alignment control device to be reciprocally movable along the linear movement guide. An information recording and/or reading apparatus allows very easy exchange of a recording/reading head and disk, and can avoid troubles such as damage to the recording/reading head and disk during exchange.