Abstract: In an optical positioning system, a holographic optical element having a plurality of rectangular apertures has predetermined ones of its aperture edges castellated or notched in order to null out undesired light energy in target areas. The apertures may be fitted with diffraction grating patterns that may also be castellated for the same purpose. A method of using the aperture and grating pattern castellated holographic optical element is also provided.

Abstract: A mechanical linkage within a computer disk drive is used to ensure that the disk drive heads are parked prior to diskette ejection. An eject frame moves with respect to the chassis and drives a latch in an arcuate path. The latch engages an actuator and drives the actuator to an inner diameter position. The mechanical linkage ensures that the actuator is captured in its parked position whenever the eject frame is in an ejected position. The latch is returned to a stowed position when a diskette is installed in the disk drive. The mechanical linkage protects the heads by ensuring proper clearances from the diskette, and by positioning the actuator in a structurally rigid portion of the receiver plate. The invention has particular applicability to disk drives for portable computers.

Abstract: A position sensor and a method of creating the same which sensor has an incoherent light source, multiple light detectors and a sinusoidal pattern that can be directly installed to the sensor. The light source and detectors are positioned along the axis of motion of the element whose position is to be determined. In a device containing such a movable target element, light from the sensor is directed through the sinusoidal pattern to and reflected from a periodic reflection profile to create detectable sinusoid signals that can be used for positioning purposes.