Abstract: An electrostatographic printing machine in which a plurality of transparencies are reproduced simultaneously on a common copy sheet.The printing machine utilizes a pair of slide projectors arranged so that they simultaneously project non-over-lapping light images of the transparencies onto the charged portion of the photoconductive member.

Abstract: Apparatus for counterbalancing the movement of a platen cover or document handler between a first closed position and a second open position. The counterbalancing apparatus comprises a gas spring and a tension spring. The tension spring is arranged to increasingly counter the force exerted by the gas spring as the platen cover is moved from the first to the second position. This compensates for the reduced force exerted by the platen cover as it is opened. The platen cover in the second position preferably has moved past vertical and the tension spring is effective to counter the force exerted by the cover between vertical and the second position.

Abstract: A variable speed, fixed wavelength magnetic imaging system is provided by generating a signal having a frequency proportional to the speed of a rotational recording member and using that signal to provide a recording frequency of fixed wavelength.

Abstract: Constant wavelength magnetic imaging is provided by generating a signal having a frequency proportional to the speed of a rotational recording member, multiplying that frequency up to a higher, desired recording frequency, and phase-locking the higher frequency signal to the unmultiplied lower frequency, thus synchronizing the recording frequency with the motor speed.

Abstract: Airborne magnetic toner is recovered from the vicinity of a magnetizable recording medium by magnetically attracting the toner with a magnetic field which does not alternate in magnetic polarity thereby magnetically polarizing the toner; and, subsequently passing the polarized magnetic toner through a magnetic field which alternates in magnetic polarity thereby decreasing the magnetic polarization of the magnetic toner. This procedure maintains the flow characteristics of the toner and avoids the clumping together of toner normally associated with magnetic recovery of magnetic toner.

Abstract: A development system for developing latent magnetic images with magnetic toner comprises a developer housing having an upper chamber communicating through a selectively variable opening with a lower chamber, the lower chamber defining the development zone and being provided with peripheral edge seals. In operation, magnetic toner is gravity fed through the selectively variable opening to the lower chamber, filling the lower chamber to provide flood contact development of the latent magnetic image residing on a magnetizable member which is moved in a direction counter to that of gravity flow. Optional baffles are preferably included in the developer housing and above the development zone to prevent machine contamination by toner powder cloud during high speed development.

Abstract: An improvement in development apparatus for developing a latent image with magnetic toner having a development zone defined at least in part by a sloping wall member along which magnetic toner migrates under the influence of gravity, residing in providing a flux channeling member affixed to the sloping wall member and within the development zone. Magnetic flux emanating from latent magnetic images passing through the development zone are channeled by the magnetic flux member and in cooperation with the magnetic toner forms a magnetic seal which prevents the flow of toner from the development zone. The present invention obviates the need to utilize a physical barrier which can cause damage to the surface of imaging members.

Abstract: A programmable controller is utilized to control a reproduction machine for producing impressions of an original on a support material. The reproduction machine includes a photosensitive member and a plurality of discrete operating components mutually cooperable with the photoreceptive member to electrostatically produce the impressions. The programmable controller incorporates a computer which operates under the direction of a master program. The computer calculates timing signals in accordance with the program information and stores the timing signals in a memory for later actuation of the components in a properly timed sequence to produce the copies desired. The machine, under the direction of the computer, periodically checks the operability of at least one of the operating components in the interval between the timing signals. Similarly, the timing signals stored in the memory are periodically updated during the intervals between actuation of the operating components.

Abstract: An imaging system wherein an imaged migration-type imaging member is provided and either the background of image areas of said image are selectively reduced to a more transparent condition. The imaged member comprises a softenable layer containing agglomerable materials in both image and complementary background configurations. Such imaged members may be provided by migration imaging techniques described herein. This member is contacted with solvent vapors capable of softening the softenable layer and heated, thereby causing the agglomerable material to selectively agglomerate in one of either the background or image areas.

Abstract: Synchronization of pixels in tracks of magnetically recorded information is provided by insuring that pixels are of substantially uniform width, particularly the first recorded pixel in each recorded track. Uniform width of pixels, particularly first pixels, is achieved through a triggering circuit which begins recording the first pixel of each track only when the record head is at the proper location. The circuit is capable of delaying the recording of a track to within a pixel length of time and divides the pixel length of time to some predetermined plurality of track recording starting points.

Abstract: A magnetic imaging system is disclosed wherein an optical image is first reduced to a graphic image by employing a magnetizable marking material followed by magnetization of the graphic image and transfer of the imagewise pattern of magnetization to a magnetic substrate to provide a latent magnetic image. The latent magnetic image is utilized for the purpose of image duplicating by successive development and transfer steps or for electronic transmission of information. Improved latent magnetic images are provided by retoning the graphic image after magnetization and further magnetizing the retoned graphic image from which the latent image is produced. Also, polishing the redeveloped graphic image further improves the quality of the latent image.

Abstract: An imaging lens system for electrostatic type reproduction machine or copiers utilizing a zoom lens effective to provide, within the magnification limits of the lens, infinitely variable image sizes.A control is provided to pre-set the lens to automatically give, upon actuation at least one preselected image size, with an override control to enable the lens to be set to provide any image size regardless of pre-set conditions.Further controls are provided for the machine nonimage erase mechanism to automatically compensate for changes in the image borders brought about by changes in image size due to resetting of the zoom lens. For this purpose, an infinitely variable edge fadeout apparatus is provided incorporating movable shutters to vary the effective size of the edge erasure slots in correspondence with image size together with timing controls for changing the operational timing of the pitch fadeout lamp in response to changes in image size upon resetting of the zoom lens.

Abstract: A composition responsive to magnetic fields and comprising a ferrofluid and metal flakes. The metal flakes align with the ferrofluid in response to magnetic lines of force and along the magnetic lines of force. Excellent contrast is provided between portions of the composition wherein the metal flakes are seen along edges or ends and portions of the composition wherein the broad surface area of the flakes are presented to view.

Abstract: A magnetic imaging system is disclosed wherein an optical image is first reduced to a graphic image by employing a magnetizable marking material followed by magnetization of the graphic image and transfer of the imagewise pattern of magnetization to a magnetic substrate to provide a latent magnetic image. The latent magnetic image is utilized for the purpose of image duplicating by successive development and transfer steps or for electronic transmission of information. Improved latent magnetic images are provided by retoning the graphic image after magnetization and further magnetizing the retoned graphic image from which the latent image is produced. Also, polishing the redeveloped graphic image further improves the quality of the latent image.

Abstract: An ink jet apparatus deposits a pattern of charged, substantially colorless droplets on an insulating imaging surface. The droplets are dried to leave an electrostatic charge pattern. The charge pattern is developed using conventional techniques and can be electronically read.

Abstract: A development system for developing latent magnetic images with magnetic toner at high speeds comprises a developer housing comprising an upper toner supply chamber communicating through an opening with a sealed developer zone.

Abstract: An imaging system wherein a migration-type imaging member comprising a softenable layer containing agglomerable migration marking material is provided, and the member is exposed to an image pattern of electromagnetic radiation of sufficient energy to cause a simultaneous imagewise migration at least in depth in the softenable layer and agglomeration of the agglomerable migration marking material in the imagewise exposed areas of the imaging member. In another embodiment, a microscopically discontinuous layer of imaging material on a stable substrate is agglomeration or evaporation imaged by the inventive system.

Abstract: An imaging member comprising an agglomerable layer on and not embedded in a substrate is agglomerated in image configuration to cause relative transparentizing or a color change and the formation of larger agglomerates in the agglomerated areas. This imaging process is followed by removal of the agglomerates from the agglomerated areas.

Abstract: An erasable optical memory array having at each storage location a non-crystalline, semiconductor threshold switching device. The threshold voltage of each switching device is strongly temperature dependent and each switching device has a finite recovery time when switched to its low resistance state. Means are provided for periodically sampling each of the switching devices with voltage pulses repetitive at a first frequency and having a first voltage level sufficient to switch to the low resistance state only those switching devices heated above room temperature by a thermal image. Additional means are provided to sample the switching devices at a second frequency greater than the first frequency and at a voltage level less than that of the first voltage level to maintain the switched devices in the low resistance state upon removal of the thermal image.

Abstract: A switching device having a movable contact that is an integral part of a metallic support substrate and is supported above the support substrate by a plurality of spring-like support legs that are also an integral part of the support substrate. The support legs extend radially outward from the movable contact and contact the substrate and the movable contact at equally spaced points. The movable contact is aligned with either a stationary contact or another movable contact and a stationary contact to provide either single or multiple switching. The switching device can be used for contact switching or capacitive switching. A plurality of the switching devices can be formed on the support substrate making the switching device particularly well suited for use in a keyboard. A portion of each support leg may be thinned to provide a negative force-displacement characteristic which provides a good tactile feedback signal indicating switching.