Abstract: In accordance with the present invention, a heater is included on an integrated circuit, together with a circuit for controlling the heater to selectively heat the integrated circuit and control the propagation delay time of signals passing through the integrated circuit. In a specific form of the invention, the propagation delay time of signals passing through at least a portion of an integrated circuit is measured and compared with a reference propagation delay time. The heater is controlled to increase the heat it produces when the measured propagation delay time is less than the reference propagation delay time. In addition, the heater is controlled to decrease the heat it provides when the measured propagation delay time is greater than the reference propagation delay time.

Abstract: An improved ink cartridge mounting system for a primary ink jet printer including an ink cartridge mounting element having four cartridge receiving openings, each specially configured to receive an ink cartridge containing ink of a particular color. A unique arrangement of six ribs extends from the outer periphery of each cartridge receiving opening to define a distinctive keying pattern adapted to seat an ink cartridge having a fluted end portion configured to mate with the distinctive keying pattern. The unique keying pattern designated for each different color are entirely complementary to a prior keying pattern employed for the same color in an alternate type of ink jet printer but for the provision of at least one additional rib.

Abstract: A first surface of a first metal component of an ink jet print head is bonded to a second surface of a second metal component of the ink jet print head, the first and second surfaces being of materials having the same or similar coefficients of thermal expansion. A layer of filler material is electroplated or otherwise placed on at least one of these surfaces. The filler material has a melting point which is below the melting point of the first and second components, and the total thickness of the filler material on the surfaces together is in the range of from approximately one-sixteenth micron to approximately five microns, with one-eighth micron to two microns being a preferred range. These surfaces are placed together and brazed under low pressure. Preferably, the braze pressure is from about one-half psi to no more than about one hundred psi, with about ten psi being most preferred.

Abstract: An optical connector in accordance with the invention includes a body to which an optical fiber supporting ferrule is mounted. A photo diode is rigidly mounted to the connector such that the photo active portion of the photo diode is optically coupled to the optical fiber. An interface is provided between the photo diode and an electronic circuit. In one form of the invention, the electronic circuit is mounted to the optical connector to facilitate this interface. Alternately, the circuit may be remote from the connector. In this case, the connector includes at least one electrically conductive wire lead for connecting the photo diode to the electronic circuit. An apertured substrate may be used to mount the photo diode to the ferrule with the photo diode optically coupled to the optical fiber through the aperture. The structure may be capped for protection against the environment, or alternatively, the circuit board itself may provide protection to the opto-electronic interface.

Abstract: A probe mount carries a probe with test points having ends in a test point plane. The probe mount is supported at three spaced apart locations by respective first, second and third supports, each adjacent to a respective one of the test points. These probe supports permit independent shifting of each of the three locations along respective parallel lines. As these locations are shifted relative to one another, the test point plane is tilted until it is parallel to a second plane containing the surface of an integrated circuit wafer to be probed. A test surface is positioned in the second plane and advanced toward the probe. As the test points contact the test surface, the test point plane is tilted. Microprocessor controlled stepper motors may be used to tilt the test point plane and to shift the test surface.

Abstract: An air-assisted drop-on-demand ink jet head 10 has a single compartment ink chamber 14 and is designed for operation over a wide range of ink drop repetition rates, including extremely high repetition rates, such as twenty kilohertz. The components included in the ink jet head have natural resonance frequencies which are greater than the desired maximum drop generation frequency of the ink jet head. In addition, the natural frequency of each of the components of the ink jet head are sufficiently different from one another to prevent intercoupling. Ink is supplied to the ink chamber 14 via a supply inlet passageway 38 which has a cross-sectional area which is sized large enough to allow the supply of ink to the ink chamber. Yet, this area is small enough so that the natural frequencies of ink in the ink inlet do not significantly alter drop generating pressure pulses in the ink chamber 14.

Abstract: An ink jet head 10 has an ink chamber 14 which receives ink from an ink inlet passageway 38. Pressure pulses applied to the ink chamber cause the ejection of ink drops from an ink drop forming orifice 23 and toward printing medium. A purging outlet 41 communicates with the ink chamber through a purging passageway 40. During purging, ink flows in a vortical path through the ink chamber 14 from the ink inlet passageway 38 to the purging outlet passageway 40. This sweeps air bubbles and contaminants from the ink chamber walls and removes them from the ink chamber. Ink pressure within the ink chamber 14 may be elevated to increase the flow of ink during purging. Also, a negative pressure may be applied to the purging outlet during purging. Variable frequency pressure pulses may also be applied to the ink chamber to assist the purging process.

Abstract: In accordance with the invention, a touch panel includes an electrically conductive film of a first resistivity which extends over a first area of a base plate. Regions of a resistivity higher than the first resistivity, such as discontinuities in the film, are positioned in this first area. These discontinuities are located so as to enhance the uniformity of an electric field which is established in a touch sensing portion of the film.

Abstract: A hollow enclosure has first and second ceramic walls interconnected and hermetically sealed by first and second compact coupling assemblies. In one form, each coupling assembly includes a first flange portion, a web portion and second flange portion. The first flange portion of the first coupling assembly is fritted to a first annular edge of the first ceramic wall. The first flange portion of the second coupling assembly is fritted to a second annular edge of the second wall. The second flanges of the coupling assemblies are then placed against one another and laser welded, without the need for thermal clamps.

Abstract: A touch panel has panel scanning signals selectively applied to the four sides of a touch sensing surface of the panel so as to establish alternating current voltage gradients in desired directions across the touch sensing surface. When the panel is touched, touch signals result and are utilized by a touch location circuit in determining the location of touch. The impedence touch current resulting from a user's touch may also be determined and used. The touch panel circuit automatically compensates for any variations in touch signals which occur when the touch panel is untouched and automatically nulls the touch signals under such circumstances to enhance the accuracy of touch location determination.

Abstract: A touch panel has panel scanning signals selectively applied to the four sides of a touch sensing surface of the panel so as to establish alternating current voltage gradients in desired directions across the touch sensing surface. When the panel is touched, touch signals or currents result and are utilized by a touch location circuit in determining the location of touch. The impedance touch current resulting from a user's touch may also be determined and used. The touch panel circuit automatically compensates for changes in impedance touch current, such as result when users touch the panel with ungloved and gloved fingers. An analog multiplier is included in the touch location circuit to improve noise rejection. Auto nulling and automatic frequency adjustment is included in the touch panel device, together with overcurrent protection circuitry.

Abstract: A touch panel has panel scanning signals selectively applied to the four sides of a touch sensing surface of the panel so as to establish alternating current voltage gradients in desired directions across the touch sensing surface. When the panel is touched, touch signals result and are utilized by a touch location circuit in determining the location of touch. The impedence touch current resulting from a user's touch may also be determined and used. The touch panel circuit automatically adjusts the frequency of the applied panel signals to shift this frequency away from fixed frequency interference spectra, such as due to cathode-ray tube flyback signals, in the environment in which the touch panel is used. The touch location thereby minimizes the effects of such spectra on touch location determinations.

Abstract: A touch panel has panel scanning signals selectively applied to the four sides of a touch sensing surface of the panel so as to establish alternating current voltage gradients in desired directions across the touch sensing surface. When the panel is touched, touch currents result and are utilized by a touch location circuit in determining the location of touch. The impedance touch current resulting from a user's touch may also be determined and used. The touch panel circuit automatically compensates for changes in impedance touch current, such as results when users touch the panel with ungloved and gloved fingers.

Abstract: In accordance with the present invention, a drum (10) has a central shaft (11) which is rotatably mounted to a drum supporting frame (12). A mount (26) pivotally connects one side (30) of the frame (12) to a cabinet (14) for pivoting about a frame pivot (73). A mount (15) rigidly secures the other frame side (32) to the base (14). An isolation mounting bracket (86) supports an optical encoder (84) in position to monitor the velocity of the shaft (11). Bracket (86) has pivots (98, 100) which cooperate with the frame pivot (73) to provide in effect a parallelogram support structure for the optical encoder (84). Thus, the encoder (84) may translate, but not rotate, in response to vibrations of the frame (12) so as to minimize or eliminate erroneous encoder velocity readings otherwise arising from such vibrations.

Abstract: An air assisted drop-on-demand ink jet head 10 has an ink chamber with an ink drop-forming orifice outlet 23 from which ink drops are generated in response to pressure waves caused by a piezoelectric crystal 56. The ink drops are carried by air outwardly through an external orifice 24 and toward printing medium. The internal orifice outlet 23 is centered in a projecting structure 48 which extends toward the external orifice 24. In one form, the projection 48 is of a frustoconical or mesa-like shape. Air flowing past the top of the projection prevents ink from wetting anything but the top of the projection, resulting in highly uniform ink drop formation with a single uniform dot being produced on the printing medium in response to each pressure wave.

Abstract: A calibration strip (80) is described for use in calibrating an optical document digitizer. The strip (80) includes an optically detectible pattern including plural discrete blocks (82) with orthogonal first and second edges (84, 86). Edges (84) are parallel to the drum axis when strip (80) is mounted to the drum (10). As the drum (10) rotates, these first edges (84) are detected and provide a reference for a Y-coordinate axis. With the drum (10) stopped, the second edges (86) are detected by a scanning array (53), as it is stepped by a motor (60) along an X-coordinate axis. The microstep location of each of the detected edges (86) is stored. During document scanning, the array (53) moves along the X-axis to the known microstep locations. The strip (80) has shaft indexing and optics magnification patterns (210, 212).

Abstract: A method and apparatus is disclosed for operating an ink jet print head 14 of the type having an air chamber 64 to which a stream of air is delivered and an ink chamber 32. A valve 48 interrupts the flow of air to the air chamber 64 from time to time, such as after each copy of a print is printed by the print head. This reduces the air pressure within the air chamber 64 and permits ink from ink chamber 32 to enter the air chamber 64 and replenish ink within the air chamber. The ink pressure is increased while the air pressure is reduced. This reduces the time required to replenish the ink. With the ink in the air chamber maintained at a consistent quantity and shape, the convergence of ink drops on printing medium is enhanced.

Abstract: An ink jet printer includes a compact ink drop generating module (10) comprising an ink jet print head (14) mounted to a body (12) which contains high and low frequency ink pressure transient suppressing mechanisms (90, 68, 80). These mechanisms inhibit the ingestion of air into print head (14) and formation of print head clogging air bubbles. The body (12) also includes a purgeble bubble trap (72). Head (14) may be of the air assisted type. Air supplied to the head pressurizes ink at one side (82) of the diaphragm (80) and at the other side (84) of the diaphragm to increase the fluid capacitance of the diaphragm. The module (10) is easy to replace as a unit.

Abstract: An ink cartridge 10 is described with a rigid, hollow housing 12 within which an ink container assembly is positioned. The assembly includes an ink container 16 mounted, as by heat sealing, directly to an ink container support 18. The support 18 is secured by fasteners 24 to a cap 14 of the housing with a gasket 22 and gasket retainer 20 positioned between the support 18 and cap 14. The gasket retainer 20 includes plural gasket retaining projections 104, 150, 152, 156 and an outer peripheral wall 23 which bears against the cap 14 when the ink cartridge is assembled. The gasket support 20 and ink container support 18 cooperatively interfit. To manufacture the ink container assembly, the ink container support 18 is inserted through an opening 74 in a sheet of ink container forming material. The portions 78 of the ink container material bounding the opening are then secured to a planar mounting surface 72 of the ink container support 18.