Abstract: The present invention is directed to a “smart earplug” capable of selectively adjusting the output of an array of acoustic wave generation elements or speakers within a user's ear canal in response to input signals, wherein at least one of the input signals has been at least partially attenuated.

Abstract: An electrostatic type voltmeter for measuring the potential on a surface, the voltmeter including a probe; a support for supporting the probe in spaced relationship with the surface, the probe having a plurality of spacing element sites thereon for measuring a distance between each of the plurality of spacing element sites and a corresponding area on the surface opposite of each of the plurality of spacing element sites; a plurality of electrostatic element sites, intermixed and adjacent to the plurality of spacing element sites on the probe, for measuring a voltage between each of the plurality of spacing element sites and an area on the surface adjacent to the corresponding area opposite of each of the plurality of spacing element sites. A processor for compensating an output signal of the probe in response to the measurements received from the plurality of spacing element sites and the plurality of electrostatic element sites.

Abstract: An electrostatic voltmeter modulator for measuring an electrostatic field between the electrostatic voltmeter modulator and a surface includes a shield, a sensing electrode, and a layer disposed between the shield and sensing electrode. The antistatic coating substantially eliminates the accumulation of electrostatic charge on the layer such that the electrostatic field measured by electrostatic voltmeter modulator substantially equals the electrostatic field corresponding to electrostatic charge on the surface. The electrostatic voltmeter modulator can be used in electrostatic imaging apparatus.

Abstract: Method and apparatus for modulating the vibrations of an object with a constant amplitude has a sensor, e.g., a piezoelectric transducer, for sensing the vibrations. A light source, e.g., an LED, receives the sensed signal and illuminates a light dependent resistor (LED) In turn, a control circuit controls the vibration amplitude in accordance with the LDR resistance. A full wave bridge rectifier can be used between the sensor and the LED.

Abstract: A system for enhancing air purging of a modulator assembly of an electrostatic voltmeter for an electrophotographic process. A vane connected to a chopper element is located at one end of a vibratory beam so as to move when the vibratory beam oscillates. Movement of the vane generates air turbulence and currents in the vicinity of the modulator and sensor electrode thereby improving purging of toner particles and other contaminants and preventing such contaminants, which tend to cause drift errors, from settling in the vicinity of the modulator and sensor electrode.

Abstract: An improved modulator assembly of an electrostatic voltmeter for an electrophotographic process. A modulator base of the modulator assembly having accurate configuration and built in design features which simplify manufacture and assembly of the modulator assembly and electrostatic voltmeter. The modulator base includes reference mounting surfaces which provide accurate orientation and alignment of the modulator assembly during assembly, air purge grooves which provide enhanced air purging of contaminants from the modulator assembly, and shielding areas which maximize the signal to noise. The modulator base provides simplified construction of a modulator assembly for an electrostatic voltmeter having enhanced performance and robust functionality.

Abstract: An electrostatic voltmeter (ESV) and a method thereof provides an electrical signal proportional to an electrostatic potential. The ESV includes a high voltage input section that receives a high voltage signal representative of an electrostatic potential. The high voltage signal input section then generates a current signal representative of the electrostatic potential. The current signal is applied to a control and sensing circuit. A high voltage current source is connected between the high voltage input section and a high voltage potential. The high voltage current source acts as an active load for the control and sensing circuit. A voltage level determining section is connected to a node between the high voltage input section and the high voltage current source for providing an electrical signal proportional to the electrostatic potential. The EVS disclosed herein is particularly useful in measuring electrostatic potential of a photoreceptor to control imaging in an electrophotographic imaging system.

Abstract: Method and apparatus for controlling amplifier gain, e.g., as used in ESV of a xerographic copier, has a light source, e.g., an LED, optically coupled to a gain control light dependent resistor (LDR). The LDR can be in a negative feedback loop around an amplifier. There is a voltage sensing probe located near the photoreceptor belt of the copier and coupled to an input of the amplifier.

Abstract: A windowed shutter on a micro-electro-mechanical system improves output current of a non-contacting electrostatic voltmeter. The output current is increased by increasing the area modulated by the micro-electro-mechanical shutter system and by increasing the speed of that modulation. The increase in the area modulated by the windowed shutter is in direct proportion to the number of windows used. Moreover, the speed of the modulation is increased by increasing the resonant frequency of the system. Less shutter mass increases the frequency thus increasing shutter movement over time.

Abstract: A sensor system for measuring physical properties of paper. The paper property sensor system includes a surface and a diaphragm opposed to each other. The small diaphragm includes a first pair and a second pair p-type piezoresistors. Each piezoresistor of the first pair has a longitudinal axis and is located perpendicular to and very close to one of the long edges of the diaphragm. Each piezoresistor of the second pair has a longitudinal axis and is located between and parallel to first pair of piezoresistors, and away from the short edges of the diaphragm. Coupling the first pair of piezoresistors with the second pair via a Wheatstone bridge produces a voltage representative of the shear force exerted by a sheet.

Abstract: An infrared reflectance densitometer (IRD) sensor which utilizes four blocks each of which generates an element of a given equation and a fifth block which generates an output voltage based on the given equation. The IRD sensor eliminates a problem known as hunting.

Abstract: A system for transporting a sheet of material including an actuator, a position sensing system, and a tactile sensor system. The actuator imparts a known force to a sheet, moving it through to the position sensing system, which measures the sheet velocity at various points. Afterward, the sheet moves through the tactile sensor system, which determines the coefficient of friction of the sheet. Given these quantities, a controller can determine the mass of the sheet, which can be used alter the performance of the sheet transport system.

Abstract: A system for measuring the mass of a sheet of material including an actuator, a position sensing system, and a tactile sensor system. The actuator imparts a known force to a sheet, moving it through to the position sensing system, which measures the sheet velocity at various points. Afterward, the sheet moves through the tactile sensor system, which determines the coefficient of friction of the sheet. Given these quantities, a controller can determine the mass of the sheet, which can be used alter the performance of a reproductive machine. A second embodiment of the mass measuring system includes an actuator, a position sensing system, and a subsystem for eliminating friction. The actuator applies a force to a sheet to move it into and through the subsystem. The position sensing system incorporated in the subsystem senses the acceleration of the sheet. Given this quantity, a controller can determine the mass of the sheet.

Abstract: A contacting electrostatic voltmeter suitable for sampling positive or negative potentials on an electrostatically charged surface. The electrostatic voltmeter includes a selectively controllable actuation mechanism that enables the use of a contacting electrostatic voltmeter to sample the surface of an electrostatically charged member, moving relative thereto, within a predetermined space. The invention finds particular use in a printing system, where it enables charge monitoring during printing yet avoids disturbance to charged latent image areas on the imaging member.

Abstract: The present invention is an apparatus for controlling the ignition of an internal combustion engine. The present invention employs a high voltage transistor, preferably a high voltage MOSFET, to switch DC voltages on the order of 1 kV to regulate the flow of current to an input tap of a primary ignition transformer or coil. The high voltage transistor is controllable by conventional logic-level voltages produced by an ignition control module.

Abstract: A non-contacting electrostatic measurement apparatus including a vibratory element and an electrode, affixed to the vibratory element, suitable for sensing a capacitive coupling relationship with an electrostatic field to produce a signal indicative of the magnitude of the electrostatic field. The signal is transmitted to signal processing circuitry via conductive fibers so as to impose little mechanical loading on the vibrating electrode. The electrode may be either unshielded, for an electrically floating electrostatic voltmeter, or shielded, for an electrostatic voltmeter employing electrically grounded components.

Abstract: An electrostatic voltmeter suitable for use in a non-contacting, positive or negative potential sensing, type electrostatic voltmeter. The invention enables a flexible, low cost electrostatic voltmeter to be produced using high-voltage field-effect transistors in the circuit design. The invention further includes input conditioning components that enable high-voltage sensing and high-voltage feedback in such a manner that processing of the input signal from the sensor is accomplished without producing a variation in the current passing through the field-effect transistor in response to voltage variations. Elimination of this variation further reduces the susceptibility of the remaining signal processing circuitry to transient direct current signals. A differential cascode as the input stage is the preferred configuration for the input conditioning components.

Abstract: A circuit which can be used to hold either the maximum or minimum voltage applied. A comparator compares the input voltage to the previous high or low and a set of two mirror circuits either charge or discharge a holding copacitor to the new value. A control circuit of transistor switches configures the circuit into either a maximum or minimum holding mode.

Abstract: An apparatus for detecting the level of material in a container. The apparatus comprises a power source and a first electrode, positioned adjacent the container, electrically connected to the power source. The apparatus further comprises a second electrode. The second electrode is spaced from the first electrode and positioned adjacent the container. The apparatus further comprises an electrical amplifier which is electrically connected to the second electrode. The amplifier amplifies a current induced in the second electrode and generates a voltage signal. The amplifier is adapted to maintain the second electrode at a virtual ground to minimize environmental impedance effects. The apparatus further comprises a rectifier, electrically connected to the amplifier, for rectifying the voltage signal and a comparator, electrically connected to the rectifier, for comparing the voltage signal to a predetermined voltage signal corresponding to the container being full with material.

Abstract: An electrostatic measurement apparatus for generating a modified electrical signal in proportion to an electrostatic potential present on a surface. The apparatus includes a sensor for producing a signal representative of the electrostatic potential on the surface. The apparatus also includes a high-voltage level shifter and a converter to transform the sensor signal into a low-voltage signal indicative of the surface potential. The electrostatic measurement apparatus is implemented using high-voltage and low-voltage integrated circuit technology.