Abstract: A sensor device having a sensor housing and a printed circuit board coupled to the sensor housing. A light emitting device is coupled to the printed circuit board. The light emitting device has an emitter face defining an emission face area. An aperture plate is coupled to the sensor housing, the aperture plate defines an aperture having an aperture area that is less than the emission face area of the emitter face. The aperture is less than 1 mm from the emitter face wherein the light emitting device is not fixed to the aperture plate. A lens is coupled to the sensor housing, having an optical axis extending through the aperture. The aperture plate is positioned between the lens and the emitter face. Boresighting angle variation across sensor components on a manufacturing line may advantageously be reduced without increased cost associated with active alignment. Irradiance drop-out may also be reduced.

Abstract: A magnetooptical disk recording device has a far-field detector for detecting radial position of a laser beam with respect to tracks on the disk. The far-field detector has a reference line dividing first and second photo detectors. The reference line is centered radially with respect to center lines of the tracks. The reference line is also center lengthwise to be tangentially center with respect to a tangential point on the track. The detector is adjustable both radially and tangentially. The tangential adjustment is based upon sensing two low reflective calibration marks on the disk that indicate centering the laser beam, hence the track tangent point, on the reference line. The calibration is based upon obtaining minimum noise in the detector output signal that signifies that the laser beam is centered on the length of the detector reference line. The calibration marks are in a mirror area disposed at one radial extremity of the disk.

Abstract: A magnetooptical disk recording device has a far-field detector for detecting radial position of a laser beam with respect to tracks on the disk. The far-field detector has a reference line dividing first and second photo detectors. The reference line is centered radially with respect to center lines of the tracks. The reference line is also center lengthwise to be tangentially center with respect to a tangential point on the track. The detector is adjustable both radially and tangentially. The tangential adjustment is based upon sensing two low reflective calibration marks on the disk that indicate centering the laser beam, hence the track tangent point, on the reference line. The calibration is based upon obtaining minimum noise in the detector output signal that signifies that the laser beam is centered on the length of the detector reference line. The calibration marks are in a mirror area disposed at one radial extremity of the disk.