Xerox Corporation

Aron Sereny

Gerald A Domoto

Stephan V Drappel

Nicholas K Sheridon

Henry R Till

Richard G Crystal

Joseph Michael Crowley

John Christopher Knights

Harold M Anderson

John M Lennon

Rodney B Proulx

Joannes N De Jong

Methods and apparatus are provided for forming images on a moving, charge retentive surface using a stream of radiant energy, modulated in imagewise fashion, wherein the intensity of the stream of radiant energy is controlled based on measured variations of the actual speed of the imaging surface from a set speed. In particular, a motion encoder, which is preferably the same motion encoder previously used to control the proper location of each line of information on the imaging surface is used to monitor the actual, instantaneous speed of the imaging surface to produce an actual speed signal. This actual speed signal is compared to a set speed signal to produce a speed variance signal which represents the difference between the actual imaging surface speed and the set speed. The variance speed signal is then used to control the intensity of the stream of radiant energy.

Imaging device which compensates for fluctuations in the speed of an

Disclosed are ionographic imaging apparatuses and processes. One apparatus comprises an imaging means, means for applying to the imaging means a liquid material capable of forming a dielectric peel layer adhering to the imaging means, ionographic writing means for generating a latent image on the peel layer, means for developing the latent image on the peel layer, and means for simultaneously transferring the peel layer bearing the developed image from the imaging means to a substrate and affixing the peel layer bearing the developed image to the substrate. In another embodiment, the apparatus employs a process which comprises applying to an imaging means a liquid material capable of forming a dielectric peel layer adhering to the imaging means, forming a first latent image on the peel layer with an ionographic writing means, developing the first latent image with a first developer, forming a second latent image on the peel layer containing the first developed image with an ionographic writing means, developing the second latent image with a second developer, forming a third latent image on the peel layer containing the first and second developed images with an ionographic writing means, developing the third latent image with a third developer, and simultaneously transferring the portion of the peel layer that bears the developed images to a substrate and affixing the peel layer bearing the developed images to the substrate. A further embodiment is directed to an apparatus and process for sequentially forming and developing primary color images on an imaging means to form a full color image, followed by trasnsferring the fully formed image to a substrate, wherein the developers employed contain a release agent.

Imaging apparatuses and processes

A system for maintaining a uniform velocity of a belt which is driven on rollers. A first roller is provided with a first encoder which supplies a pulse train to a first control device which controls a first servomotor. The first servomotor drives the first roller which provides torque to the belt. A second roller is provided with a second encoder which supplies a pulse train to a second control device which controls a second servomotor for selectively dampening the second roller. When a variation in the speed of the belt is detected by the second control device a signal is sent from the second control device to the second servomotor. The second servomotor dampens any speed variations so that the belt maintains a constant speed at a location proximate to the second roller.

Damping servo-motor control

A method and apparatus is described for removing excess liquid from an image receptor. As the image receptor moves at a certain velocity in one direction, a vacuum source or a source of positive air pressure effects air flow in a direction parallel to and opposite that of image receptor movement. The air flow is effected at a velocity greater than that of the image receptor movement. A channel is defined adjacent the receptor surface in which a pressure gradient is established for driving the air flow and causing the liquid layer to thin.

Removal of excess liquid from an image receptor

A thermo-optic light modulation array is disclosed for use in an imaging system of an electrophotographic printer to produce electrostatic latent images. The array comprises a light transmitting medium arranged in contact with an array of pixel shaped heaters which are selectively energized in response to digitized data signals for pulse heating the portions of the medium in vicinity of the heaters. Temperature gradients in the medium produced by the energized heaters cause changes in the index of refraction of the medium, so that selected portions of a sheet of collimated light directed through the temperature gradients in the light transmitting medium are deflected or modulated. The modulated light may be blocked by a stop and the unmodulated light may be directed to the precharged photoconductive member of the printer to form the latent images or visa versa. Several modes of light modulation are disclosed. In one mode, the light is directed through the medium just above and closely adjacent the heaters in a grazing fashion. A second transmissive mode directs the light through both the medium and transparent heaters, while a third reflective mode directs the light through the medium into reflective surfaces on the heaters. The reflective mode of modulation may be either for the production of linear, one-dimensional lines of picture elements or for the production of full two-dimensional alpha-numeric information. The other modes produce latent images one line of picture elements or pixels at a time.

Thermo-optic light modulation array

An ink jet printhead for use in a thermal ink jet printer having bubble-generating heating elements formed symmetrically around the entrances to passageways in the ink-holding printhead chamber that terminate as nozzles. The heating elements are individually addressable with current pulses to form vapor bubbles, which, during collapse, produce an impact force that expels and propels droplets toward a recording medium. An alternate embodiment includes an ultrasonic generator in the printhead chamber to produce pressure waves in the ink contained in the chamber. The current pulse applied to the heating element is synchronized with the lower pressure wave to obtain bubble growth with substantially lower temperatures resulting in a more energy efficient printhead.

Cavitational liquid impact printer

A thermal ink jet printhead ejects ink droplets on demand by utilizing the conservation of momentum of collapsing bubbles in a layer of liquid ink having a predetermined thickness. The printhead has an ink containing chamber with an array of individually addressable heating elements on one chamber interior surface which are aligned with an elongated opening in a parallel, confronting chamber wall. The spacing between the chamber wall with the elongated opening and the chamber surface with the heating elements provide the desired ink layer thickness. Selectively addressed heating elements momentarily produce vapor bubbles in the ink layer. When the bubbles collapse radially inward towards their respective heating elements, an oppositely directed force perpendicular to the heating element is generated which is large enough to overcome the surface tension of the ink in the elongated opening and propel a droplet of ink therefrom towards a recording medium.

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Briarcliff Manor, NY, United States of America

Aron Sereny