Abstract: The present invention (50) corrects duty-cycle errors generated by imperfections in encoder scales and encoder detectors. A preferred embodiment of the invention operates by detecting successive transparent-to-opaque transitions of the encoder scale (20), calculating the distance between the transitions, dividing that distance by two, and generating a synthetic encoder pluse that is timed to represent a position 50 percent of the distance between the transparent-to-opaque transitions.

Abstract: A drop-on-demand ink jet has an ink chamber coupled to a source of ink, and an ink drop orifice with an outlet. An acoustic driver produces a pressure wave in the ink and causes the ink to pass outwardly through the ink drop orifice and outlet. The driver is driven with bipolar drive pulses having a refill pulse component and an eject pulse component of a polarity which is opposite to the refull pulse component. The refill and eject pulse components are separated by a wait period. The drive pulses may be adjusted to minimize their energy content at a frequency corresponding to the dominant acoustic resonance frequency of the ink jet. This will accelerate drop breakoff, optimize drop shape and minimize drop speed variations over the range of drop printing rates. The ink jet printer of the present invention may be used to print with a wide variety of inks, including phase change inks to achieve high print quality at high print rates.

Abstract: A micromechanical sensor comprises a support, a micromechanical element that is movable relative to the support under the application of a stimulus, and a transducer. The transducer comprises a first component carried by the micromechanical element and movable therewith, and a second component stationary relative to the support. One of the first and second transducer components is a member for establishing a magnetic field and the other of the first and second transducer components is a SQUID positioned in the magnetic field for detecting variation in the magnetic field due to relative movement of the micromechanical element and the support.

Abstract: A print head, formed with spaced linear subheads of jet nozzles, prints all of the lines or image element rows on a print medium such as a sheet of paper by scanning along the face of the sheet. The head is advanced between scans by an equivalent number of lines generally equal to the number of nozzles in the head, whereby all print lines are addressed only once. Apparatus for printing includes the use of pointers in registers to keep track of head structure and location on a print medium for calculating print addresses. A partial page memory is used which wraps around to the beginning from the end. An edge sequence control logic circuit modifies the print data so that nozzles not over the image area do not print. A positive printer carriage position encoder uses an index marker located in the middle of a strip of incremental markers. Sensing of the index marker resets an up/down counter with a value that gives a positive value for all count conditions.

Abstract: A drop-on-demand ink jet print head (9) has an ink pressure chamber (22) coupled to a source of ink (11) and an ink drop ejecting orifice (103) with an ink drop ejection orifice outlet (14). An acoustic driver (36), in response to a driver signal (100), produces a pressure wave in the ink and causes the ink to pass outwardly through the ink drop ejecting orifice (103) and the ink jet ejection orifice outlet (14) of the ink jet print head (9). In accordance with the present invention, controlling the operation of the ink jet print head (9) with a particular drive signal reduces print quality degradation resulting from rectified diffusion, which is the growth of air bubbles dissolved in the ink from the repeated application of pressure pulses to the ink residing within the ink pressure chamber (22) of the ink jet print head (9), such pressure pulses causing the application of pressures below ambient pressure.

Abstract: A projection lens assembly (10) projects onto a display screen (38) electrons emitted from an output side (86) of an electron multiplier such as, for example, a microchannel plate (70). The projection lens assembly includes a dome-shaped mesh element (16) that is concave as viewed from the display screen. The mesh element is positioned between the microchannel plate and a filter element (20) having a beam-limiting aperture (22). The mesh element is of an aspherical shape that allows the projection lens assembly to project the electrons toward the display screen with substantially no spherical aberration, thereby forming near the beam-limiting aperture an electron beam crossover of small diameter. The beam-limiting aperture is formed with a relatively small diameter that allows the filter element to block electrons of energies outside a preselected range of energy values, thereby reducing chromatic aberration in the image formed on the display screen.

Abstract: A drop-on-demand ink jet has an ink chamber coupled to a source of ink, and an ink drop orifice with an outlet. An acoustic driver produces a pressure wave in the ink and causes the ink to pass outwardly through the ink drop orifice and outlet. The size of the ink drops may be varied, such as by driving the acoustic driver with varying drive signals, preferably comprising individual or combinations of plural bipolar drive pulses. The ink jet printer of the present invention may be used to print with a wide variety of inks, including phase change inks.

Abstract: A dual output balun distributes substantially all of the available power in a single ended input signal applied thereto (less small parasitic losses) equally to two or more pairs of push-pull output terminals (or vice versa).

Abstract: A compact ink jet printer is described utilizing a small drum for carrying a sheet of record medium during the printing operation. In one embodiment, the drum has an exterior surface with a high coefficient of friction with a contact roller retaining the record medium against the drum as the drum is rotated. Printing is accomplished as by jetting ink from an ink jet print head onto the medium while the medium is backed up by a fixed platen. A fusing mechanism may be utilized to flatten ink drops on the printed medium. A drive mechanism for an ink jet printer may include a stepper motor coupled by timing belt sprockets and a timing belt to the drum of the printer. These components may be selected such that the drum is incremented a multiple of a pixel height during each step of the stepper motor. The record medium may also be clamped to a drum by a clamping mechanism and rotated through plural revolutions of the drum during respective printing and fusing steps.

Abstract: Print heads are formed with spaced subheads having nozzles such that all of the lines or pixel rows on a print medium such as a sheet of paper are printed by scanning of the print head along the face of the sheet. The head structures include three subheads, each having nozzles for printing one or more adjacent lines with the subheads being spaced the same number of lines apart as the number of lines each prints; and three subheads spaced the equivalent of seven lines apart, each subhead having three nozzles spaced at the equivalent of alternate lines. The heads are advanced between scans by an equivalent number of lines generally equal to the number of nozzles in the head, whereby all print lines are addressed only once. Apparatus for printing includes the use of pointers in registers to keep track of head structure and location on a print medium for calculating print addresses. A partial page memory is used which wraps around to the beginning from the end.

Abstract: A method for producing a light-transmissive printed substrate is provided. The substrate is printed with a predetermined pattern of a light-transmissive phase change ink which initially transmits light in a non-rectilinear path. When the pattern of solidified phase change ink is subsequently reoriented to form an ink layer of substantially uniform thickness, a printed image layer is formed which will transmit light in a substantially rectilinear path and is suitable for overhead projection.In some instances the adhesion between the ink image layer and the substrate is not as high as is desired. This problem can result in delamination of the ink from the film under certain conditions. In order to overcome this problem, an intermediate optically clear adhesion promoting layer is introduced between the light-transmissive phase change ink and the base substrate.

Abstract: A detection circuit (30, 32) for carrying out a rapid search technique for locating the position of a stylus (12) relative to a display screen (10). A microprocessor (34) and related components select a group of light detectors (20, 28) that are positioned near the display screen (10). The summed output current of the selected group of detectors (20, 28) is monitored to determine whether the output of any detector in the selected group is reduced because of the presence of a stylus (12). Whenever the selected group shows such reduction in output current, that selected groups is divided into two subgroups. The subgroup having reduced current output due to the presence of the stylus (12) is further divided until the particular detector(s) having reduced output current is found, the position of the detector is correlated to the location of the stylus (12) relative to the screen (10).

Abstract: A flexible circuit board is formed from a sheet of polyimide having a contact pad on its first side and a continuous layer of copper on its second side by removing copper from the second side so as to leave at least one discrete island that confronts the pad through the sheet of insulating material, and applying force to the island in the direction from the second side toward the first side, whereby the island is deformed plastically to form a dimple and the pad is deformed plastically to form a bump.

Abstract: A roll type fixing and developing apparatus in which sheet material to be treated is passed through a high pressure nip defined by a pair of rollers and a roller for such apparatus, is described. The roller includes an elongated tubular shell with a pressure applying external surface, an elongated core positioned within the tubular shell, and an elastomeric material disposed between the core and shell to support the shell on the core. The core may be of a number of configurations and may increase in transverse cross-sectional dimension from the respective ends of the core toward the center of the core. The core may taper continuously or in discrete steps from its center toward its first and second ends. In addition, the core may have a longitudinal cross section with a crown in the shape of a beam deflection curve for a simply supported, uniformly constant cross-section beam. The shell may be similarly configured along its interior surface.

Abstract: An extremely compact ink jet print head has an array of closely spaced nozzles which are supplied from densely packed ink pressure chambers by way of offset channels. The ink supply inlets leading to the pressure chambers and the offset channels are designed to provide uniform operating characteristics to the ink jet nozzles of the array. To enhance the packing density of the pressure chambers, the ink supply channels leading to the pressure chambers and offset channels are positioned in planes between the pressure chambers and nozzles. An optional ink purging pathway is provided for purging bubbles and other contaminants from the chamber side of the nozzles. The ink jet print head may be assembled from plural plates with features in all but the nozzle defining plate being formed by photo-patterning and etching processes without requiring machining or other metal working.

Abstract: The present invention entails an accurate, sensitive, and stable means of mounting a print head to a movable carriage assembly of the type used in computer output printers. The invention uses one pair of planar mounting surfaces and one pair of angled mounting surfaces between the print head and the carriage of a print head assembly. A pair of pivoting clamping plates apply a force that urges both pairs of mounting surfaces together while simultaneously providing adjustment of the translation of the print head relative to the carriage. The translation across the oppositely angled surfaces on two of the four mounting surfaces provides an accurate azimuthal angle adjustment for the print head. Because the other mounting surfaces are in the same plane, the translation affects only the azimuthal angle.

Abstract: Printing is by an array of color-printing elements or nozzles in order to produce interlaced color printing while printing each line only once with each color. Print head array configurations for printing two, three and four colors include linear and parallel arrays. In one embodiment, a first color and a second color are printed on alternate lines of a first set of print lines. The first color and a third color are printed on alternate lines of a second set of print lines. Also, the second color and the third color are printed on alternate lines of a third set of print lines. By sequentially printing these consecutive sets of lines on a print medium, with each of the three pairs of colors, all of the lines of an image are printed once with each color. Other color-printing configurations are also shown.

Abstract: A cathode-ray tube (10) includes a prefocusing lens (14) and an adjacent high-voltage einzel focus lens (16) to form an electron beam with low spherical aberration. The high-voltage einzel focus lens includes a central lens element (52) positioned between a pair of outer lens elements (54) and (56). The outer lens elements receive a common high-voltage potential of more than about 12 kilovolts. The prefocusing lens includes a G3 electrode positioned between an anode (48) and a first one of the outer lens elements of the einzel focus lens. The G3 electrode receives the high voltage applied to the outer lens elements. In a preferred embodiment, the G3 electrode is a flat end disc plate (57b) on the end of the first one of the outer lens elements.

Abstract: An apparatus for and a method of addressing data storage elements (16) employs an ionizable gas to address the storage elements for storing data in and reading data out of them. The storage elements are defined by the overlapping areas of multiple column electrode (18) extending in a common direction on a first substrate (48) and multiple channels (20) extending in a common direction on a second substrate (54). A layer of dielectric material (46) separates the first and the second substrates, which are positioned face-to-face and spaced-apart with the direction of the channels transverse to that of the column electrodes. Each of the channels is filled with an ionizable gas and includes a reference potential electrode and a row electrode electrically isolated from each other.

Abstract: An automatic gain control circuit for an interferometer or a phase sensitive detector reduces sensitivity to fluctuations in amplitude of input signals. A pair of currents from the phase sensitive detector that represents a detected phase difference are input to an automatic gain control ratio detector. The output of the automatic gain control ratio detector is a function of the ratio of the difference and sum of the phase sensitive detector currents that is substantially independent of intensity or amplitude fluctuations of the input signals.