Abstract: A novel liquid composition for developing latent electrostatic images whereby to form a gap between the developed image and the carrier sheet to which the developed image is to be transferred. The composition is such that it contains both charged and uncharged spacer particles. The spacer particles are of larger diameter than the toner particles so as to form a gap between the developed image and the carrier sheet to which they are transferred. The spacer particles, furthermore, have a specific gravity lower than the specific gravity of the carrier liquid, which may be a low-boiling hydrocarbon. This is accomplished by having a gas bubble enclosed in a portion of the material of which the spacer particles are formed, which material is preferably glass. The charged spacer particles may be coated with a polymer of which the toner particles are formed. Both the coated spacer particles and the toner particles bear the same charge. The remainder of the spacer particles are substantially uncharged.

Abstract: The invention comprises a method of transferring a liquid-developed electrostatic image across a gap to a carrier sheet accompanied by heating of the carrier sheet, either before or after transfer, to a temperature at which the binder or polymer forming the toner particles will solvate in the liquid entrained in the transferred image to increase the density of the image. Thus temperature is above ambient temperature but below 100.degree. C. The composition comprises an insulating dispersant liquid through which is disseminated a pigmented waxy binder or polymer which is insoluble in the dispersant liquid at room temperature but will solvate in the dispersant liquid at elevated temperatures.

Abstract: A facsimile scanner in which each successive line of an original is scanned by firing a light-reflective or light-refractive spherical projectile along a path over which an optical image of that line is formed to produce a time-varying pattern of reflected or refracted light from the projectile as it traverses the path. A photodetector responsive to light diverted from the projectile provides the facsimile signal. In the recording mode, each successive line of a facsimile signal is recorded by illuminating the same projectile with light modulated by the facsimile signal as the projectile traverses its path to produce a spatially varying pattern of reflected or refracted light, an optical image of which is formed on a recording medium such as the photoconductor of an electrophotographic copier.

Abstract: A developing system for an electrophotographic copier in which a roller having a conductive outer surface is disposed adjacent to the imaging surface to form a gap. The roller is driven at a peripheral linear velocity substantially greater than the velocity of movement of the imaging surface and is supplied with liquid developer at a location spaced from the gap to cause the roller to inject the developer into the gap. The roller is coupled to a source of potential through a gas discharge tube to maintain the potential of the electrode within predetermined limits.

Abstract: Sheet detecting apparatus for use in sheet feeders in which sheets are fed through first and second pairs of feed rollers longitudinally spaced from each other by less than the length of a sheet. The presence of a sheet spanning both pairs of rollers is sensed by driving the downstream pair of rollers at a slightly greater linear speed than the upstream pair of rollers and sensing at the second pair of rollers the retarding torque transmitted through the sheet of paper from the first pair of rollers.

Abstract: A cleaning system for a liquid developer electrophotographic copier includes a roller formed with a body of resilient material, such as a closed-cell elastomer, having externally exposed, internally isolated surface cells. The roller is mounted to extend across the imaging surface in contact therewith and is driven to move the roller surface relative to the wet imaging surface to scrub the imaging surface and concomitantly under the action of the roller surface open cells to draw from the imaging surface liquid carrying toner effectively to dry the imaging surface. A small-radius edge is disposed in trailing engagement with the roller surface to deform the roller material sufficiently from the surface cells to be carried away for reuse or disposal.

Abstract: A developed electrostatic image is transferred from a support to a carrier sheet over a gap of between twenty and seventy microns. The gap is formed by dusting onto the developed electrostatic image particles of such size as to form the required gap or by providing protuberances on the insulating support, which may be a photoconductor. The protuberances on the support or the majority of dusted particles are spaced apart by four millimeters or less.

Abstract: A breech for the gun of a microballistic printer comprising a plurality of metal spheres positioned on the inside periphery of a cup, forming a central opening slightly smaller than the spherical projectiles used in the microballistic printer. The spheres are held in spaced relation by a projectile which is adapted to be sequentially replaced by another projectile during the operation of the microballistic printer. The spheres forming the central opening through which the projectiles pass are sealed with a sealing compound to prevent the loss of gaseous pressure which is built up behind the projectile and which propels it toward the printing surface.

Abstract: Apparatus for individually feeding sheets in which a friction feed roller positively driven in the direction of feed opposes a friction retarding roller biased in the reverse direction with a predetermined torque and urged against the feed roller with a predetermined force. The reverse bias torque is regulated by means of a spring and a controllable clutch which is disengaged in response to a predetermined strain in the spring. The spring and controllable clutch may comprise a helical spring clutch. In another aspect of the disclosure, the retarding roller is carried by an arm for rotation about a pivot center located such that the normal force urging the two rollers together is automatically suitably adjusted in response to changes in the biasing torque.

Abstract: A copier employing liquid developer in which the lower portion of a deep well in the liquid carrier extends downwardly into the space between a pair of shock absorbing machine base plate mounts to receive the supply of liquid developer for the machine. A motor housing in the upper portion of the well extends downwardly to approximately the upper level of liquid in the lower portion of the well when it contains a full charge of liquid. Each of a cleaning fluid supply motor and a developer electrode supply motor in the housing has a shaft which extends downwardly to a respective pump disposed in the liquid supply to drive the pumps respectively to supply liquid to the cleaning station and to the developer station. A splash plate extending over the top of the well prevents the escape of liquid from the well even with the machine at an appreciable angle from the horizontal. Shields are provided at various locations on the machine to prevent the accidental escape of liquid.

Abstract: A magnetically actuated clutch in which a helical spring is carried by an input clutch member with portions surrounding a relatively rotatable output clutch member. An electromagnet is positioned with its poles lightly engaging the surrounding spring portions at circumferentially spaced locations, while either the spring or the output clutch member or both are formed of a magnetically permeable material to complete a magnetic circuit. Energizing the electromagnet causes the poles to clamp the spring to retard its rotation with the input member, thereby causing the spring to wrap down on the output clutch member and engage the clutch.

Abstract: Apparatus for separating a copy sheet from a photoconductive imaging surface in an electrophotographic copier following image transfer in which a plurality of guides are stationarily disposed at transversely spaced locations across the imaging surface at sufficiently small spacings therefrom to intercept the leading edge of a copy sheet moving past the guides and separate the sheet edge from the surface. The guides are disposed at progressively retarded positions relative to the movement of the imaging surface to effect laterally progressive peeling of the leading edge of the copy sheet from one lateral edge to the other and have such progressively decreasing lengths along arcuate guide paths as to compensate for their progressively retarded positions and direct the sheet onto an exit path with a leading edge orientation corresponding to its original orientation in the transfer station.

Abstract: I provide an improved method of transferring a developed latent electrostatic image from the surface of a photoconductor to a carrier sheet adapted to receive the developed image, apparatus for carrying out the method, an improved carrier sheet for use in the method, a method of making the carrier sheet, and apparatus for forming the carrier sheet. The method comprises providing spacing means between the surface of the photoconductor and the carrier sheet adapted to receive the image, which spacing means extend from the surface of the carrier sheet a distance less than seventy microns and more than the depth of the developed image on the photoconductor. The gap prevents squeezing and deforming of the image and, when a liquid developer is used, prevents the carrier sheet from becoming unduly moistened except by liquid entrained in the charged toner particles forming the developed image.

Abstract: My invention comprises a large capacity combined magazine and sheet feeder for copying machines, in which the sheet being fed is brought to feeding level by a spring-powered mechanical servomechanism. The assembly is adapted to be substituted for a small capacity cassette on an existing copy machine and to employ the power and logic of the existing machine to feed sheets from the large capacity assembly in proper synchronized relationship. This is accomplished by a power take-off from the copy machine with which the improved magazine is being used, which power take-off can be installed without altering the original machine. The large capacity unit then feeds sheets to the copy machine as if the original small capacity cassette were being used. The magazine is adapted to handle sheets of various lengths on which copies are to be made.

Abstract: Photocopier scanning apparatus wherein a scanning carriage is mechanically driven by a pair of flexible cables acting on the carriage at widely spaced points on either side of its center of gravity. The cables may be electrically conductive to energize an illuminating lamp mounted on the carriage. The carriage rests on glass slides having arcuate surface portions and is further urged thereagainst by forces from permanent magnets. The carriage is resiliently biased to return to an initial position. The velocity with which the carriage returns is limited; and the return velocity is further damped adjacent the initial position.

Abstract: My invention comprises a ballistic impact printer which includes a gun for successively propelling balls along predetermined paths to trace a desired character on a medium supported on a platen spaced from the gun. Means are provided for orienting the gun after each ball leaves the muzzle of the gun so that the desired pattern is formed. Gas under pressure propels a ball along the bore of the gun, which is slightly larger than the diameter of the ball. This enables me to make the gun out of resilient material, since a gas bearing is formed which prevents a ball from touching the sides of the bore while it is traveling down the bore. The breech of the gun is slightly smaller than the diameter of a ball, so that a ball acts as a seal for a chamber in which gas pressure is being built up. When a ball in the breech is dislodged by a succeeding ball, gas from the chamber performs its propelling action between the time the ball is dislodged from the breech and the succeeding ball is seated in the breech.

Abstract: Apparatus for receiving and stacking a large number of sheets such as electrophotographic copies in which the height of a support to which sheets are successively delivered is adjusted in response to a photodetector arranged to sense the height of the stack of sheets on the support. The sheet support is raised and lowered by rotating a lead screw engaging a follower carried by the support and is limited in its excursion by stops on the follower which circumferentially intercept stops carried by the lead screw to prevent further rotation of the screw.

Abstract: Apparatus for synchronizing the aiming and firing of the solid projectile gun of a microballistic printer or the like. In the preferred embodiment, a microphone acoustically coupled to an inlet used to supply pressurized air to the ball gun senses the pressure drop occurring in the ball gun pressure chamber when a ball is fired. The microphone output is used by the ball gun control system to determine when the ball has left the ball gun, allowing the ball gun to be redirected at a new target location. In alternative embodiments of the invention, a microphone disposed adjacent the muzzle of the ball gun and an optical detector are respectively used to sense when a ball has been fired.

Abstract: A multilayer photoconductive assembly with an intermediate heterojunction. The assembly comprises a conductive substrate, a thin semiconductive layer formed of a material of one carrier polarity, which material has a narrow band gap. This layer is in substantially ohmic (low-resistive) contact with the conductive substrate. A light-absorbing layer is formed of a semiconductor which is thicker than the first layer and is of a carrier polarity opposite to the polarity of the first layer. The material has a band gap wider than the band gap of the first layer. The first and second semiconductive layers form a rectifying heterojunction therebetween. This enables the assembly to have a tremendously increased dark resistance and produces an assembly enabling high-speed electrophotography.

Abstract: An electrophotographic photoconductor, formed on a conductive substrate by spray pyrolysis, comprising essentially a major amount of cadmium sulphide and a minor amount of zinc sulphide. The cadmium layer is at least three microns in thickness and is formed in three zones. The zone adjacent the metal substrate, adapted to form a contact layer, bears an amount of lead sulphide; the outermost zone, adapted to absorb light, is doped with a minor amount of copper to eliminate fatigue; and the intermediate zone, which is necessary to increase the surface potential, is adapted to transport light-generated charge and is doped with a minor amount of chlorine. The process is carried on in the atmosphere with three different aqueous solutions of reagents to form the three different zones. The photoconductive layer is microcrystalline in structure and bears adsorbed oxygen.