Abstract: A method for determining whether a user having a communications device has encountered a perilous situation includes detecting a sound with the communications device and determining whether the sound is indicative of the perilous situation. The method generates a query with the communications device for the user when the sound is determined to be indicative of the perilous situation and waits for a response from the user via the communications device. The response or lack thereof is capable of confirming the perilous situation or a false alarm.

Abstract: Current supplied to a group of components is selectively sensed so that the current supplied when a particular component is the only active component can be compared to a reference current indicative of proper component operation. If there is a discrepancy, an alert can be generated. Can be applied on a larger scale to allow isolation of a subsystem, then a group within the subsystem, then a component with the group, etc.

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: A method of maintaining consistent large solid area development by developing a large area test patch covering the image area of a photorececptor and detecting the lead edge and trail edge density of the test patch using a densitometer to measure reflectance and comparing the lead and trail edge density to the lead and trail edge density of a reference patch. The reference patch is generated after the changing of developer elements such as developer material and photoreceptor and an electrostatic set up performed. Alternatively a density differential between lead and trail edge density of the test patch is detected. Electrostatic parameters such as preset toner concentration control values and decreasing the development field of the test patch are adjusted to maintain constant large solid area development.

Abstract: Direct electrostatic printing apparatus including a cylindrically shaped donor structure for delivering imaging material such as toner particles to a printhead forming an integral part of the printing device. The printhead structure includes control electrodes and a shield electrode structure secured to opposite sides of an insulative base. The donor structure has a relatively small diameter compared to such devices of the prior art making it impossible to deliver adequate quantities of toner to some of the printhead apertures using electrical biasing techniques of the prior art. In the device disclosed, the printhead apertures are biased according to the aperture spacing from the donor structure. The magnitude of the bias or its duration applied to the apertures farther from the donor structure surface is such that toner delivery to those apertures is equal to that of all other apertures.

Abstract: A system for printing gray levels without needing to use halftone cells. An architecture is disclosed for controlling printing elements to deposit a variable amount of toner onto a given area of paper. The architecture includes a pixel memory for determining a gray level for each pixel in a row, and a counter for incrementing a gray level. A comparator compares a memory location corresponding to a certain pixel with the output of the counter, and the comparison result is then applied to a printing element corresponding to the pixel.

Abstract: Direct electrostatic printing apparatus including structure for delivering developer or toner particles to a printhead forming an integral part of the printing device. The printhead structure includes control electrodes and a shield electrode structure secured to opposite sides of an insulative base. The radius of the opening of a control electrode is smaller than the radius of a corresponding shield electrode opening resulting in larger peak potentials for controlling toner flow for the same voltage applied to the control electrode of a printhead aperture wherein the control electrode opening is larger than the opening in a corresponding shield electrode opening.

Abstract: Direct electrostatic printing (DEP) is enhanced by the provision of wrong-sign toner extraction holes or apertures provided in a printhead structure at a location which is upstream of the printing apertures. Wrong sign toner particles are extracted from a cloud of toner provided from a toner delivery device. The wrong sign toner is extracted from the powder cloud before the cloud reaches the vicinity of the printing apertures thereby minimizing print hole blockage.

Abstract: Direct Electrostatic Printing apparatus including structure for removing wrong sign developer particles from a printhead forming an an integral part of the printing device. The printing device includes, in addition to the printhead, a conductive shoe which is suitably biased during a printing cycle to assist in the electrostatic attraction of developer passing through apertures in the printhead onto the copying medium disposed intermediate the printhead and the conductive shoe. During a cleaning cycle, the printing bias is removed from the shoe and an electrical bias suitable for creating an oscillating electrostatic field which effects removal of toner from the printhead is applied to the shoe.