Abstract: System for use in testing includes a frame positionable on a person's head, a display section, and a combiner arranged at least partly in front of the eyes of the person and which allows simultaneous viewing of an environment in front of the person and content on the display section, e.g., test questions. A crossview camera system images from locations on each lateral side of the frame toward the opposite lateral side and below the combiner. An iris camera system images the eyes of the person. A forward-looking camera system images an area in front of the frame. A processor analyze images obtained by the crossview camera system to determine presence of imaging devices, images obtained by the iris camera system to determine position of irises of the person and optionally imaging devices, and images obtained by the forward-looking camera system to determine presence of specific objects.

Abstract: Device for use in testing includes a frame positionable on a person's head, a display section, and a combiner arranged at least partly in front of the eyes of the person and which allows simultaneous viewing of an environment in front of the person and content on the display section, e.g., test questions. A crossview camera system images from locations on each lateral side of the frame toward the opposite lateral side and below the combiner. An iris camera system images the eyes of the person. A forward-looking camera system images an area in front of the frame. A processor analyze images obtained by the crossview camera system to determine presence of imaging devices, images obtained by the iris camera system to determine position of irises of the person and optionally imaging devices, and images obtained by the forward-looking camera system to determine presence of specific objects.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.