Abstract: A high bandwidth amplifier circuit with input protection is achieved by providing a signal limiting diode circuit in the path to the positive input of the amplifier and a cross-over signal feed path for coupling a portion of the input signal from the input signal source side of the signal limiting diode circuit to the negative input of the amplifier. To maximize the overall circuit bandwidth and minimize VSWR and noise, the cross-over signal feed path is designed to couple over to the negative input of the amplifier a signal that has at a higher-end of the bandwidth range an increasing amplitude and increasingly leading phase relationship relative to the amplitude limited version of the input signal being coupled to the positive input of the amplifier. In a desirable embodiment, most of the circuitry is contained on an integrated circuit and bond wires needed for coupling serve as inductors and tune the circuitry.

Abstract: A video effect is created with a video processing machine having a plurality of functions, each of which has a state that is selectively variable in response to change in an associated function parameter. The method comprises selecting a set of functions, specifying a starting keyframe containing a starting value for each of the parameters, specifying an ending keyframe containing ending values for the parameters associated with the functions of the selected set and vacancies for the other parameters associated with other functions, and specifying a number of video frames. The starting keyframe is used to place the machine in a starting state, in which each function has the status defined by the value of its associated parameter in the starting keyframe, and a first video frame is processed with the processing machine in the starting state.

Abstract: An improved media-width phase-change ink-jet print had (102) maintains a uniform temperature across its width to produce consistent drop mass and uniform print quality. The print head uses a heater (120) including two separately controlled, overlapping heating zones (154). The heating zones produce heat gradients (170, 172) that have maximum outputs toward opposing edges (168a, 168b) of the print head and are controlled in response to thermistors (138s, 168b) positioned at the corresponding edges. The two heating zones together produce a linear heat gradient (180) across the print heat to compensate for uneven head-to-drum spacing (166) and other unsymmetrical thermal loads on the print head. The improved print head also includes baffles (192) that reduce air flow between the head and the attached reservoir (118), and thermal breaks (218) that insulate the section (220) of the head that includes the jets from the thermal gradients at the edges of the print head.

Abstract: A spectrum analyzer (10, 70) employs a method of reducing the amplitude of harmonic and spurious signals (102, 104, 112) introduced into a frequency-domain output spectrum by, for example, nonlinearities in a mixer (12, 78) or an ADC (20, 92). The method employs acquiring and digitizing a normal time-domain data record of an input signal, transforming the time-domain data record to a normal frequency-domain record (30), and storing the normal record. Next, a local oscillator (14, 76) driving the mixer is frequency shifted, and an additional time-domain data record is acquired, digitized, transformed, and stored to produce a shifted frequency-domain data record (40). Then, the shifted data record is mathematically realigned (50) with the normal data record and the normal and realigned data records are combined to produce a frequency-domain data record (60) having reduced harmonic and spurious signal amplitudes.

Abstract: A graphic display for chroma keyer controls presents background hue as a radial spoke of an outer chroma vector circle, with selectivity being displayed as a wedge about the radial spoke. Foreground suppression may be added to the graphic display by providing a concentric inner chroma vector circle with the foreground suppression hue being a radial spoke of the inner circle and foreground selectivity being a wedge within the inner circle about such radial spoke. That portion of the outer circle that is overlapped by the inner circle is suppressed, or rendered invisible, so that the background chroma information appears as a torus about the inner chroma vector circle.

Abstract: A phase modulator circuit and method for generating an output signal having individually positionable edges is described. The phase modulator includes a programmable pulse generator, such as an interval counter, a delay, or a ring oscillator for producing the output signal, and a control value source, such as a memory, for delivering a sequence of control values to the generator. The control values determine the time between successive output pulses. A programmable interval counter includes a free running counter, the output of which is compared to a control value, preferably stored as a modulo data value, to generate an output pulse. A first programmable delay circuit includes a ring oscillator having plural delay lines for fine control of edge positioning. To fully synchronize the delay circuit to a coarse control interval counter, the clock input to the interval counter can be provided by the ring oscillator.

Abstract: Improved color ink-jet printing is accomplished by an ink-jet nozzle array configuration (32, 110) which has an odd number of nozzles (34) that are uniformly spaced apart by two line widths (2 V) such that naturally interlaced printing is accomplished when a print head (54) employing the nozzle array configuration is moved in uniformly stepped intervals. A color ink-jet print head employing the array configuration further employs multiple horizontally spaced apart instances (30) of the array in which each array ejects a particular color of ink, and the nozzles of each array are aligned in the direction of scanning to eject ink toward a common band of lines.

Abstract: An image transfer ink-jet printer employs an image receiving drum that rotates relative to an ink-jet array print head spanning the full width of the drum. A print head positioner moves the print head in precise increments to position adjacent scan lines of ink drops. Without affecting the overall scale of the image, adjacent pairs of scan lines are spaced at distances less than one nominal pixel width. Pairings within the range of 0.2 to 0.5 pixel widths are used, with optimal spacing at 0.35 pixel widths.

Abstract: A mechanical optical switch having opposing first and second optical transmission paths, such as optical fibers, forming an optical interface and rotating about respective independent and offset first and second rotational axes for positioning the fibers on respective first and second offset and intersecting closed curves operates to rotate the input or first optical fiber on its closed curve to one of the two intersecting points on its closed curve in response to the angular coordinate representative of the position of fiber at the intersecting point matching the intersecting point of the second optical fiber. The output or second optical fiber is rotated on its closed curve to the intersecting point corresponding to the intersecting point of the first fiber in response to the angular coordinate representative of the position of the second fiber at the intersecting point. These rotational movements may be performed sequentially, but in the preferred embodiment they are performed simultaneously.

Abstract: The angular coordinates representative of intersecting points on closed curves of a first optical fiber axially offset from a plurality of optical fibers in a mechanical optical switch are determined by imaging respective end faces of opposing first and second mounting members containing the respective fibers for determining the locations of the optical fibers in the mounting members and at least one reference point within one of the mounting members. The relative angular coordinates of the intersecting points between each of the closed curves of the plurality of optical fibers and the closed curve of the first optical fiber are aligned as a function of aligning the first optical fiber with the reference point. One of the plurality of optical fibers is optimally aligned with the first optical fiber at one of the intersecting points on the closed curves using the adjusted relative angular coordinates as the starting angular coordinates.

Abstract: An addressing structure (10, 10') using an ionizable gaseous medium has plural nonintersecting channels (20, 20') extending in a first direction and filled with an ionizable gaseous medium. Each channel contains a reference electrode (30, 30') and a row electrode (62, 62'). An amplifier (100) provides a kicker pulse to one or both of the first and second electrodes in a channel at a time coincident with the application of a second electrical signal to the second electrode. The kicker pulse and the second electrical signal cooperate to promote ionization of the gaseous medium within a predetermined discharge initiation delay time tolerance. The ionization captures across a liquid crystal material (44) data signals placed on column electrodes (18); the data signals place display elements (16) associated with the electro-optic material in predetermined data storage or display element states.

Abstract: Fractional pixel motion estimation of video signals is performed by comparing a block of pixels from a current image of the video signal with a plurality of displaced blocks within a search window from a previous/future reference image of the video signal via a distortion function. The displaced block from the reference image that produces the minimum value for the distortion function provides a center pixel. A general surface is fitted around this center pixel so that it equals the distortion function at each integer pixel location surrounding the center pixel. The distortion function for the fitted surface is estimated for fractional pixel locations, and the motion vector corresponding to the minimum value for the fractional distortion function is selected for transmission as part of the compressed video.

Abstract: A phase change ink composition is disclosed wherein the ink composition utilizes polymeric dyes in combination with a selected phase change ink carrier composition.

Abstract: A high-frequency calibration method and circuit including a dual path step attenuator. A calibration system is provided having a switch between the user signal input and the instrument input and an amplifier between the calibration signal input and the instrument input. The amplifier provides signal conditioning. The output of the amplifier is connected to the instrument input through a switch and a resistor, the resistor isolating the switch from the instrument input so as effectively to prevent degradation of the user input signal. A sense amplifier provides a calibration signal output indicative of the input impedance of the instrument input in response to a known stimulus. The input of the sense amplifier is isolated from the instrument input by a resistor. A current source provides a known stimulus to the instrument input to measure input impedance. A step attenuator is provided having an attenuated path and an unattenuated path.

Abstract: A media sensing system monitors the movement of media along the media pathway (76) as a sheet of printing medium (56) is transported through the printer 50. The media sensing system permits a hand fed sheet of printing medium (56) to be detected by a sensor (302) and signal to be sent to inactivate a print media pick roller (122) that automatically feeds print media. The sensing system senses the transport of print media (56) by print media transport rollers (140, 142) detecting media sheet size, activates the transfer process of an image from the liquid intermediate transfer surface on the transfer drum (54) to a sheet of print medium (56) after pausing the sheet of print medium to synchronize its movement along the media pathway with the imaging process, and activating the preheater (60) to heat the print medium (56) prior to image transfer and fusing. The sensing system senses the exit of the print medium (56) from the media exit rollers (212, 220) for delivery to an output tray (68).

Abstract: A number format conversion apparatus for signal processing has as inputs an exponent value and a mantissa value, the exponent and mantissa values representing a numerical value for a signal sample. An operator inputs an exponent max/min range and an offset, depending upon what conversion is desired. An output exponent is derived from the input exponent as a function of the maximum and minimum exponent values and the exponent offset. A shift value is derived from an unclipped output exponent and the minimum exponent value. The shift value is applied to a barrel shifter to shift the mantissa value to produce an output mantissa. The output exponent and mantissa form a floating point output number for the signal sample when a floating point output is selected, and the mantissa forms a fixed point output number for the signal sample when a fixed point output is selected.