Abstract: An electro-optic display cell and method of making the same is disclosed herein. The display cell has an arrangement of display electrodes in contact with a liquid within a sealed enclosure. The enclosure comprises an impervious transparent cover and a rigid structural wall member. A seal between the cover and wall member and an elastomeric plug extending between the exterior and interior complete the enclosure. The cell is filled by injecting the liquid into the presealed enclosure by perforating the plug with hollow needles also employed to remove entrapped gas. Upon withdrawal of the needles the perforations collapse to self-seal the enclosure but for added integrity the plug is also mechanically clamped. The seal and plug can be formed as an integral elastomeric moulding around a frame member forming the side wall of the enclosure and the frame member clamped between the cover and a separate base.

Abstract: An oscillating pneumatodynamic bearing takes the form of a laminated transducer disk cooperating with a flat surface or a tubular transducer cooperating with a rod or an enclosing tube. Such bearings are also known as squeeze bearings. At least one piezoelectric, magnetostrictive or electrostrictive material is laminated with another material to provide oscillation of the transducer portion of the bearing so that the transducer portion is able to fly above a bearing surface on a fluid which is usually ambient air compressed by the mechanical oscillation of the transducer portion at an ultrasonic frequency. The disk or the tube is connected mechanically to supports and to its electrical sources of energy or signals at points along the loci of zero oscillation or minimal oscillation. With a laminated disk, a nodal circle is the locus of zero oscillation.

Abstract: Completion of potentiostatic erasure of an electrochromic display is detected by monitoring the erase current supplied to addressed display electrodes by potentiostatic erase drive means. The occurrence of a fall in erase current, corresponding to completion of the erasure of the addressed display electrodes, is detected, preferably by a threshold detector, and an erase completion indication produced. This indication effects disconnection of the erase current path.

Abstract: A fiber optic light pen has been adapted for high resolution use with an interactive display of a computer system. The body of the light pen, which is adapted to be hand held, includes a slightly movable tip for engaging a display screen. When so engaged, a screen sensor within the body signals to the computer system that the pen is in contact with the screen. A principal fiber optic element or conduit within the pen body collects light emitted by the screen without the use of any imaging optics and a two-threshold light detector responding to two different amplitude levels of collected light permits separate and high resolution determination of the vertical and horizontal positions of the light pen with respect to the screen.

Abstract: An actuator for a magnetic read/write head carried by a linear motor has its stator located between a pair of disks within a stack of magnetic recording disks. The stator comprises an array of reversed polarity magnets (preferably permanent) in a linear array. A pair of flat coils are the drive elements of the armature of the motor with the coils arranged in side-by-side relationship for bridging from magnet to magnet in the stator. Thus the armature will not be stalled between magnets. The actuator is controlled by an electronic control system for selecting any position precisely, rather than in steps as in a stepping motor. A microprocessor can be used to adjust control of the direction of motion of the actuator based upon feedback signals.

Abstract: The radial position of a transducer used to read and/or write information into or write information into or from a spinning information storage disk (optical or magnetic) is servo controlled by an optical doppler interferometer mounted at least in part for common movement with the transducer. The optical doppler interferometer measures the instantaneous linear velocity of the information storage disk at the position of the transducer (or at a fixed relative position with respect to the transducer) and the position of the transducer is controlled so as to make the measured instantaneous linear velocity follow a reference signal corresponding with the desired information storage track.

Abstract: This is a static photometric polarimeter for use with a sample S upon which a beam passed through a beam splitter (which reflects the beam to a detector D.sub.o) and which beam is 45.degree. polarized. The reflection of the beam from the surface of sample S is passed to a polarizing beam splitter with one portion of the reflected beam going to a detector D.sub.s which measures the perpendicular polarization component of the beam and the other portion of the beam going to the detector D.sub.p which measures the parallel polarized portion of the reflected beam.

Abstract: A method and apparatus for wireless cursor position control is disclosed herein. The apparatus comprises a wireless cursor position device and a separate control base whereby the direction and velocity of motion of the position device is monitored by the control base and used said direction and velocity of motion is to calculate the relative motion of the cursor on the display system. The method and apparatus operates by transmitting and receiving ultrasonic and infrared signals between the position device and control base and thereby calculating the movement of the position device from an initial location by measurement doppler shift of the signals. An output signal to the display system is then generated to move the cursor in correspondence with the motion of the position device.

Abstract: A hermetic electro-optic display cell has an enclosure for a liquid electrolyte comprising a wall of a plastics material, a lower inorganic base and an upper window both of which are impervious to the electrolyte. Impervious gasket means seals at least the lower edges of the wall to the base when clamped together. To render the wall hermetic an inorganic coating is provided around the exterior faces and along the edges at least as far as the gasket means. Metal is the preferred coating except for transparent faces where silica may be employed.

Abstract: A liquid-filled electro-optic display cell employs an elastomeric diaphragm to seal a filling orifice in the cell side wall. The orifice is surrounded by a rim and the diaphragm is retained over the rim in such a way as to seal the orifice while remaining free to flex over central portions of the orifice. This retention may be effected by means of an annular washer and clamping pin. In this way, sealing is effected and thermal expansion accommodated. The cell is filled by turning it until the orifice is uppermost and filling it until a convex meniscus is formed above the rim to ensure that the diaphragm seals the orifice without introduction of bubbles.