Abstract: A drive circuit produces a drive signal for a device having a piezoelectric actuator. In some example embodiments, the drive circuit dynamically changes the drive signal (e.g., a shape of the waveform of the drive signal) during real time operation of the device. In the same or distinct other example embodiments, the drive circuit generates the drive signal in accordance with an analog input signal to the drive circuit. The analog input signal can be or bear, for example, an indication of resonance of the piezoelectric actuator; an indication of temperature; an indication of viscosity; and/or, an indication of one of a desired voltage and a desired frequency of the drive signal. The analog input signal can be obtained from a user input device. In the same or distinct other example embodiments, the drive circuit generates the drive signal in dependence upon an operational parameter of the device.

Abstract: A drive circuit (18) senses a parameter of a piezoelectric actuator (14) operating in a device (10) and adjusts a drive signal of the piezoelectric actuator in accordance with the parameter. The drive circuit comprises a controller (100) which controls a drive signal applied to the piezoelectric actuator (14); a feedback monitor (122) which obtains a feedback signal from the piezoelectric actuator while the piezoelectric actuator works; and, a processor (116) which uses the feedback signal to determine the parameter of the piezoelectric actuator. In one example mode, the parameter of the piezoelectric actuator which is determined by the piezoelectric actuator drive circuit is the capacitance or dielectric constant of the piezoelectric actuator. In other example modes, the parameter of the piezoelectric actuator which is determined by the piezoelectric actuator drive circuit is impedance or resonant frequency of the piezoelectric actuator.

Abstract: A gravity-type sensor device comprising a switch which monitors the position of an object over a three dimensional pathway which extends dimensionally about all three orthogonal axes where the object may be tilted, rotated or inverted, as well as translated through space rather than maintained at a fixed location, so as to provide a signal to indicate that the object is moving in the correct three dimensional manner, whereby the switch is disposed within an external housing in a manner that allows the position of the switch to be altered relative to the housing, thereby allowing the angle or plane of the pathway to be adjusted when the housing is attached to different objects.

Abstract: A gravity responsive attitude switch containing electrical contacts separated by a gap, the switch containing a bead liquid and a carrier liquid, the two liquids being immiscible and having different electric resistivity values, where the liquid bead may be disposed between the contacts by properly positioning the switch. The contacts are connected in an electronic circuit which senses the difference in resistivity dependent on whether the bead liquid or the carrier liquid is bridging the gap between the contacts, which in turn determines whether an operative electric circuit is opened or closed.

Abstract: A three-axis gravity switch having a curved chamber to retain a gravity responsive member such as a ball of liquid mercury, the chamber having a three-dimensional pathway defined on at least one of its walls, where the gravity responsive member and pathway are conductive, either electrically or optically, such that a circuit is completed when the gravity responsive member contacts the pathway, where the switch can be rotated, inverted and translated in three dimensions such that the pathway defines an acceptable three dimensional course of rotation for the switch.

Abstract: A system, method, and apparatus for obtaining the corneal topography of an object using computer analyzed rasterstereographic images. The object may be nontransparent and diffusing, or it may be transparent and nondiffusing, such as a cornea. Rasterstereographic images of a cornea are produced by staining the cornea with a fluorescein solution which projects a light and dark line pattern onto the cornea through a grid. When obtaining the topography of a cornea, several different filters are used for producing and obtaining a grid image. An image processor uses unique software to store and analyze data extracted from the grid pattern. A video camera, an illuminator, the filters, and the grid may be mounted on a microscope. One embodiment uses a grid with vertical lines. Another embodiment uses a grid having intersecting horizontal and vertical lines for exhibiting surface details in a two-dimensional x-y plane.

Abstract: A system, method, and apparatus for obtaining the corneal topography of an object using computer analyzed rasterstereographic images. The object may be nontransparent and diffusing, or it may be transparent and nondiffusing, such as a cornea. Rasterstereographic images of a cornea are produced by staining the cornea with a fluorescein solution which projects a light and dark line pattern onto the cornea through a grid. When obtaining the topography of a cornea, several different filters are used for producing and obtaining a grid image. An image processor uses unique software to store and analyze data extracted from the grid pattern. A video camera, an illuminator, the filters, and the grid may be mounted on a microscope.