Abstract: A push-pull Class E amplifier is used to provide an efficient transfer of power to the induction coil in an electrodeless discharge lamp and to reduce the amount of radio frequency interference emitted by the lamp into the surrounding environment. A bifilar or other type of multifilar induction coil, preferably center-tapped, is used to further reduce the radio frequency interference problem.

Abstract: A putter alignment system (10) is provided for use in aiding in practicing golf putting. The system (10) includes a putter component (12) mounted on a golf putter (12) and a remote target component (14) situated along the desired relative alignment axis (18) from the putter (20). Electronic components are utilized to determine relative alignment of the putter (20) to the target by analyzing an reflected slot beam (16). The preferred embodiment includes an emitter (68) on the remote target component (14) and a cylindrical subsection reflector (50) of one of several acceptable configurations on the putter component (12) to created and delimit the beam (16). The reflector (50) is mounted on the putter (20) so as to be perpendicular to the putter axis (49) such that on perfect alignment a the slot beam (16) will coincide with the alignment axis (18).

Abstract: A structure and method for controlling a liquid crystal display takes advantage of the sharp reflectance change over a small voltage change for new liquid crystal display materials, applying ON and OFF pixel voltages very close to the transition voltage of the liquid crystal material and regulating the applied voltage to remain reliably near and on the desired side of this transition voltage. Also, a net zero DC voltage across pixels of the crystal is maintained using a switching mode close to half the frequency of prior art modes. Driving voltages are provided by a switching regulator rather than the prior art voltage divider, resulting in a significant reduction in operating power. The preferred switching regulator generates only three additional voltages for driving rows and columns of the display, in contrast to the five generated voltages of the prior art voltage divider.

Abstract: To desensitize the write channel of a direct read after write optical memory from time dependent changes in the operating characteristics of the hardware and from time and position dependent variations in the performance characteristics of the recording medium, the present invention provides a real time feedback system for adjusting the output power of the write laser or similar source and/or for adjusting the modulation timing of the write beam so as to null out any unwanted dc component that is exhibited by the recorded data during the direct read after write process. In other words, the feedback stabilizes the timing of the transitions in the recorded data.

Abstract: The stiffness of a second-order damped servo system with position and velocity feedback circuits is increased without affecting the command response, damping factor, or natural frequency of the system by adding an acceleration feedback circuit and maintaining a specified relationship between the effective gain of the acceleration feedback circuit and the effective gain of the servo driver.

Abstract: In a disc drive which does not have a head position sensor but does have a velocity detector and off-track error detection means for sensing the distance and direction of the displacement of the head from the nearest track center, and in which the direction signal from the error detector is of one polarity for odd numbered tracks and of the opposite polarity for even numbered tracks, a system is provided for capturing a track on a blind seek which involves detecting deceleration of the head to below capture velocity, allowing the head to drift past the next track center while sensing whether that track is odd or even, and then initiating a capture of the next following track on the basis of whether the detected track is odd or even and the direction of seek.

Abstract: In a tracking system using an error signal derived from recorded dipulses of opposing polarity on each side of the center of a data track recorded on a magnetic medium, the need for highly accurate signal integration is avoided by partially integrating the dipulse signal, and then integrating the partially integrated signal above a predetermined threshold. The resulting double-integrated signal provides an error signal substantially unaffected by DC and noise offsets. A double-ended average pulse detector with feedback using a double-ended "current mirror" to carry out the described method is disclosed.

Abstract: In connection with a head positioning device for magnetic disc drives in which a low cost implementation for seeks of varying lengths is important and optimum seek time is secondary, a system is disclosed in which head velocity, at least during the final portion of the deceleration phase, is a linear function of the distance remaining to target. In addition, the system lends itself to the approximation of optimum seek time on long seeks by commanding a velocity curve whose slope exceeds the maximum deceleration of the torquer for all but the final portion of the seek distance so as to provide a maximum acceleration-deceleration profile until just prior to the target, and a final deceleration at a decreasing rate as the head approaches the target.