Abstract: An incandescent lamp socket comprises a housing for receiving the base portion of an incandescent lamp and switch means for selectively connecting the lamp's contacts to a source of electrical energy. Such switch means comprises a rotatably mounted cylindrical sleeve which surrounds the socket housing, and means responsive to rotational movement of the sleeve relative to the housing for selectively connecting the lamp contacts to the energy source. Preferably, such connecting means comprises a planetary ring gear disposed along the interior wall of the sleeve, a cooperating pinion gear mounted for rotational movement on the socket housing, cam means rigidly coupled to the pinion gear and rotatable therewith, and electrically energized cam follower means, movable in response to the cam means to selectively energize certain socket electrodes which are connected to the contacts of a lamp supported by the socket housing.

Abstract: An improved method of optically writing and/or reading high density information involves: (1) predeterminedly positioning a flat, uniformly thick, flexible, optical disc with respect to an axis of rotation; (2) rotating the disc on such axis at a high speed and in a predeterminedly spaced relation to a predeterminedly shaped, smooth, featureless reference surface and (3) coupling a central region between the disc and reference surface to an ambient gas source. Related apparatus and disc configurations, including embodiments having flexible disc covers, also are disclosed.

Abstract: A variable light attenuator comprises a pair of spaced optical elements, each having a reflective surface and at least one being adapted to variably polarize a light beam as a function of its angle of incidence. Means are provided for rotatably supporting the optical elements so that the beam, upon being reflected from both elements, is always parallel to the input beam, regardless of its angle of incidence. Preferably, a second pair of reflective elements, similarly structured, arranged and supported, cooperates with the first pair of reflective elements to produce a variably attenuated output beam which is colinear with the input beam.

Abstract: Skiving apparatus for use in electrographic copiers for stripping magnetically attractive developer from the outer sleeve of a magnetic brush applicator. Such apparatus comprises an elongated and flexible skive blade and means for applying equal and opposite axial forces at spaced locations along the blade to produce tension in the skive blade and thereby provide a straight skiving edge. Preferably, the skive blade is made of a magnetically attractive material so that it is attracted toward the magnetic core piece of the brush applicator.

Abstract: A dual-tech intruder detection system includes a pair of intruder-detecting subsystems, each functioning to detect intrusion by a technology different from the other, and apparatus for activating an alarm in response to both subsystems detecting intrusion within a predetermined time interval. A supervisory circuit serves to detect a malfunction in one of the subsystems. Default apparatus, responsive to the output of the supervisory circuit, causes the alarm activating apparatus to activate an alarm in response to the still functioning subsystem's detection of intrusion.

Abstract: Disclosed is apparatus for scavenging charged particles (e.g. triboelectrically carrier particles) from an electrographic recording element. Such apparatus comprises a conductive grid positioned in close proximity to the path of the recording element, and biasing means for electrically biasing the grid so as to attract the charged particles from the recording element yet prevent them from depositing on, and thereby contaminating, the grid.

Abstract: A document printer includes sheet-feeding apparatus for sequentially presenting both faces of a print-receiving sheet to a print station. According to a preferred embodiment, such apparatus features, as part of the duplex sheet path, reversible sheet-feeding means operable in first or second active modes for selectively feeding sheets into and out of a chute, located upstream from the feeding means, to reverse the sheet's lead edge/trail edge orientation. Such sheet-feeding means is also operable in a passive mode in which it allows sheets to advance, without substantial interference, downstream therepast to a registration position.

Abstract: A magnetic brush apparatus for use in electrographic copiers and the like for applying magnetic developer to electrostatic images at a development zone to effect development of such images. Such apparatus includes a non-magnetic sleeve having a rotatably driven magnetic roller therein, and magnetic shunt means for selectively reducing the magnetic field produced by the magnetic roller outside the sleeve. By reducing the magnetic field shortly after the developer first contacts the image and maintaining the reduced field until the developed image is advanced beyond the influence of the magnetic roller, a trailing edge development artifact is avoided.

Abstract: Apparatus for controlling the replenishment of toner in an electrographic reproduction apparatus includes means for monitoring toner concentration in an electrographic developer mix, and means for monitoring the rate of toner depletion from such mix in developing electrostatic images. The outputs of such monitoring means are algebraically summed to provide a control signal for controlling toner replenishment.

Abstract: A method for writing and/or reading information on an optical recording element, such as an optical disk, utilizes a recording element comprising a recording layer having physical and optical properties which are optimized for phase-shift read-out. The optical properties of the recording layer give rise to a non-linear relative phase shift/layer thickness curve which, in combination with a predetermined nominal thickness of the recording layer, enhances the signal-to-noise ratio of the read-out signal.

Abstract: An electrographic development apparatus comprises a magnetic brush applicator having cooling means for dissipating thermal energy from the developer as it is transported by the brush. Such cooling means preferably comprises means for passing a cooling fluid through the interior of the brush while in use. Alternatively, such cooling means comprises a hollow skive through which a cooling fluid is circulated.

Abstract: An optical write/read unit includes a support, an overlying record layer that is constructed for writing or reading with a predetermined light wavelength(s) and is absorptive to light of other wavelengths and a protective cover means that is selectively transparent to light of at least one of said predetermined wavelength(s). In one embodiment the disc unit is adapted for writing and reading with the same light wavelength and the cover means blocks other light wavelengths. In another embodiment the disc unit is adapted to reading with light of wavelength substantially different than the writing wavelength and the cover means selectively transmits the operative (write and read) wavelengths and selectively blocks a large proportion of other light wavelengths. In another embodiment the cover means is selectively transmissive to the reading wavelength and is displaceable to permit writing light onto the record layer.

Abstract: An optical disk unit, of the kind having a record element and a flexible cover sheet that are attached around an outer periphery in a manner providing an outer spacing and a generally enclosed inter-space therebetween, has an improved construction which significantly reduces the likelihood of contact between the record element and cover sheet. Central spacing means provide a central sheet-to-element spacing that is significantly larger than said outer spacing and vent means, into and out of the inter-space cause a reduction in the spacing between the record portion of the element and the cover sheet during write/read operation. The air flow through the vent means also reduces the formation of visible debris in the enclosed record element/cover sheet inter-space.

Abstract: The quality of spot-focus of optical writing and reading light upon the information surface of a flexible optical disc is passively enhanced by (1) rotating the disc with its neutral plane stabilized in space and (2) directing such light through the optical disc support into precise spot-focus on the information surface. With this technique spherical aberration induced by the disc support compensates for thickness variation of the support. Various structural embodiments are disclosed.

Abstract: Debris suppression is effected in a sealed disk unit, of the kind having a generally enclosed record element/cover sheet inter-space, by controlling the temperature gradient across the inter-space so that thermophoretic forces, exerted by air molecules, drive ablative debris particles toward the cover sheet.

Abstract: Disclosed herein is a self-regulating hydrant which is characterized by a mechanism which automatically alters the flow of fluid through a valve seat in response to changes in ambient temperature. A temperature-responsive member, operatively coupled to a valve plug, is used to control the position of the plug relative to a valve seat. As the temperature of such member changes, its dimensions change. Such dimensional changes are preferably amplified and used to move the plug relative to the valve seat to control the rate of fluid flow through the valve seat.

Abstract: Optical disc write/read apparatus and systems of the type having a flexible record disc and turntable which interface in a manner forming a generally enclosed space between record portions of the disc and opposing turntable portions is provided with inner and outer ventilation means which effect a continuous, controlled air flow through said space during write/read operations.

Abstract: Apparatus for facilitating the safe disposal of used hypodermic needles. According to a preferred embodiment, a funnel-like member, adapted to be hand-held, functions to support a needle sheath during a needle-sheathing operation. The converging walls of such member shield the hand of the user from accidental "needle sticks". Also disclosed are needle containers which incorporate means for facilitating the sheathing of used needles prior to entering the container.

Abstract: Spot-focus of a write or read beam upon a flexible optical disc, which is rotated with its neutral plane highly stabilized in space, is maintained precisely by moving the write or read beam source (e.g. a laser diode) in response to focus error signals.

Abstract: Disclosed herein is a multiple field-of-view optical system which is adapted for use in electromagnetic radiation-responsive systems, e.g. in passive infrared intruder detection systems. The optical system features an array of optical wedges which are arranged and constructed to intercept radiation propagating toward an optical axis from a plurality of discrete fields of view and refract such radiation in a direction parallel to such axis. A reflective focusing element, preferably parabolic in shape and positioned on said axis, intercepts the radiation refracted by the wedge array and redirects it toward the reflector's focal point. According to a preferred embodiment, the reflective element and wedge array are mounted for relative movement to alter the direction of the various fields of view.