Abstract: An RF jack and plug assembly provides 360.degree. of contact with a strong mechanical bond between the two parts. The jack has molded and stamped interrelated parts that predeterminedly position the parts for simple and accurate assembly. The construction provides positive electrical contact and long life for the contact elements with complete RF shielding.

Abstract: In the embodiment described in the specification, a hot melt ink image on a substrate is treated in a continuous manner by moving it along a platen having a heating zone to melt drops of hot melt ink and cause them to spread on the substrate. The platen has a flat central portion and curved portions at each end with curvatures sufficient to prevent formation of cockle. At the output end of the heating zone, the substrate is moved continuously into a quenching zone where a cooling platen cools the substrate by thermal contact at a rapid rate to prevent crystallization or frosting of the hot melt ink image. After the quenching zone, the substrate is moved along a surface having a reverse curvature with respect to the curved portions of the heating platen to eliminate residual curvature of the substrate resulting from the curved portions of the heating platen.

Abstract: A thin-film transducer ink jet head is prepared by oxidizing one surface of a silicon wafer to provide a dielectric layer, forming electrodes on the layer by photoresist processing techniques, depositing one or more layers of PZT material to provide a thin-film piezoelectric layer having a thickness in the range of 1-25 microns, forming another pattern of electrodes on the surface of the PZT layer by photoresist techniques, and selectively etching the silicon substrate in the region of the electrodes to provide an ink chamber. Thereafter, an orifice plate is affixed to the substrate to enclose the ink chambers and provide an ink orifice for each of the chambers. An ink jet head having chambers 3.34 mm long by 0.17 mm wide by 0.15 mm deep and orifices spaced by 0.305 mm is provided.

Abstract: A machine for precisely painting large numbers of small various sized tubular pieces. The painting machine includes a chain driven track assembly which moves the tube pieces held on paint fixtures into a paint chamber for painting and into an oven to dry the paint to the tube.

Abstract: In the representative embodiments of the invention described herein, a transducer for an ink jet system includes a piezoelectric element with an array of spaced interdigitated electrodes on one side of the element. One embodiment includes two such arrays disposed near the sides of the ink jet chamber and another array of interdigitated electrodes on the opposite side of the transducer in the central region of the ink jet chamber. In that embodiment, continuous electrodes are provided on the surfaces of the transducer opposite to the surfaces bearing the interdigitated arrays. Alternate electrodes in each array and the continuous electrode on the opposite side are grounded and positive or negative potential is applied to the other electrodes in the arrays to produce deflection of the transducer element and alternate pulses of opposite polarity may be applied to polarize the piezoelectric element in opposite directions with each pulse.

Abstract: In the representative ink supply system described in the specification, continuous circulation of ink in an ink jet head is accomplished by providing two reservoirs connected to each ink jet orifice through corresponding passages so that ink flows continuously from a high-level reservoir past the orifice to a low-level reservoir. The difference between the levels of ink in the reservoirs is maintained relatively constant by inertial pumping during reciprocal motion of the ink jet head or by pressure transfer of ink from one reservoir to the other reservoir. Cross-flow purging of air or debris from the ink jet head is effected by covering the ink jet orifices and applying air pressure to one reservoir to cause ink and any trapped air or debris to flow from the head to the other reservoir. A pump responsive to reciprocal motion of the ink jet head generates a positive air pressure which is applied during purging and a negative air pressure which is applied to a deaerator for removing dissolved air from the ink.

Abstract: In the particular embodiments of the invention described in the specification, a transparency includes a transparent substrate made of a polyester material, a colored ink pattern disposed on one surface of the transparent substrate in the form of three-dimensional ink spots having curved surfaces, and spots of a colorless ink made of a material which has an index of refraction approximately the same as that of the colored ink spots deposited in overlapping relation to colored ink spots as to reduce the dispersion of light by those ink spots. In one embodiment, the colorless ink spots are located in regions having no colored ink spots and in another embodiment the colorless ink spreads to a greater extent than the colored ink.

Abstract: In the embodiment of the hot melt ink supply unit described in the specification, a block of solid hot melt ink has a peripheral surface formed with a key configuration and a handle is removably connected to the block by a threaded projection. After insertion of the block into a correspondingly keyed opening in a heated reservoir, the handle is turned to separate the handle portion from the block of solid ink. A container provided with a removable seal encloses the block of solid ink and handle to protect the ink from contamination.

Abstract: In the embodiment described in the specification, a hot melt ink coating such as an image on a substrate is treated in a continuous manner by moving it along a platen having a heating zone to melt drops of hot melt ink and cause them to spread on the substrate. The platen has a flat central portion and curved portions at each end with curvatures sufficient to prevent formation of cockle. At the output end of the heating zone, the substrate is moved continuously into a quenching zone where a cooling platent cools the substrate by thermal contact at a rapid rate of at least 50.degree. C. per second to prevent crystallization or frosting of the hot melt ink image thereby minimizing light transmission losses. After the quenching zone, the substrate is moved along a surface having a reverse curvature with respect to the curved portions of the heating platen to eliminate residual curvature of the substrate resulting from the curved portions of the heating platen.

Abstract: In the particular embodiments of the invention described in the specification, an opaque subtractive color ink reflection print having improved color purity resulting from reduced frosting and crystallization of the ink layers is prepared by reheating the ink image to a temperature above the melting point of at least one of the inks and then quenching the image by cooling it at a rate of at least 50.degree. C. per second. In one embodiment, the ink image is produced by an ink jet head applied to a substrate supported on a platen maintained at least 20.degree. C. below the melting point of the inks to inhibit spreading of the inks into the substrate, and the image is thereafter heated to a temperature at least 20.degree. C. above the melting point of at least one of the inks for a period of 3 to 5 seconds and then quenched at a rate of 500.degree. C. per second to produce an image having less than 20% light loss resulting from scattering of light by frosting and crystallization of the ink in the layers.

Abstract: In the representative embodiments of the invention described in the specification, an ink jet head has a series of aligned arrays of ink jet orifices arranged to project drops of different colored inks in sequence to the same location on a substrate during each scan of the ink jet head adjacent to the substrate. The spacing of the orifices in each aligned array and the speed of the ink jet head during the scanning are arranged so that all the ink drops applied at the same location on the substrate are applied in a time period of no more than about 100 milliseconds and preferably no more than 50 milliseconds. Moreover, to avoid banding the lines produced by successive scans of the head are interlaced so as to produce a periodic frequency of no more than about four lines per millimeter.

Abstract: In the particular embodiments described in the specification, a hot melt ink jet system includes a temperature-controlled platen provided with a heater and with a thermoelectric cooler electrically connected to a heat pump, and a temperature control unit for controlling the operation of the heater and the heat pump to maintain a substrate on the platen which receives the ink at a temperature which provides a desired spot size without causing print-through. In certain embodiments, the substrate temperature is from about 20.degree. C. above to about 20.degree. C. below the melting point of the ink and is determined by subtracting half the difference between the jetting temperature and the temperature at which the ink has a viscosity of about 200-300 cp from the latter temperature.

Abstract: In the embodiment described in the specification, a hot melt ink image on a substrate is treated in a continuous manner by moving it along a platen having a heating zone to melt drops of hot melt ink and cause them to spread on the substrate and decrease the angle of contact of the drops with the surface of the substrate. The platen has a flat central portion and curved portions at each end with curvatures sufficient to prevent formation of cockle. At the output end of the heating zone, the substrate is moved continuously into a quenching zone where a cooling platen cools the substrate by thermal contact at a rapid rate to prevent crystallization or frosting of the hot melt ink image. After the quenching zone, the substrate is moved along a surface having a reverse curvature with respect to the curved portions of the heating platen to eliminate residual curvature of the substrate resulting from the curved portions of the heating platen.

Abstract: In the embodiment of the hot melt ink supply unit described in the specification, a block of solid hot melt ink has a peripheral surface formed with a key configuration and a handle is removably connected to the block by a threaded projection. After insertion of the block into a correspondingly keyed opening in a heated reservoir, the handle is turned to separate the handle portion from the block of solid ink. A container provided with a removable seal encloses the block of solid ink and handle to protect the ink from contamination.

Abstract: In the particular embodiment of a device for removing dissolved gas from ink described in the specification, an elongated ink path leading to an ink jet head is formed between two permeable fluorine-containing membranes. The membranes are backed by air plenums which contain support members to hold the membranes in position. Reduced pressure is applied to the plenums to extract dissolved gas from the ink in the ink path without accumulating scum on the membrane surfaces. Increased pressure can also be applied to the plenums to eject ink from the ink jet head for purging. Within the ink jet head, ink is circulated convectively from the orifice to the deaerating path even when the jet is not jetting ink.

Abstract: In the particular embodiment of the invention described in the specification, a hot melt ink print is prepared by applying the ink to a porous substrate, permitting it to solidify, and reheating the substrate and the ink to a temperature 5.degree. C. to 30.degree. C. above the melting point of the ink for 0.5 to 10 seconds. In one embodiment, the porous substrate is supported on a platen which is maintained at least 30.degree. C. below the melting point of the ink to prevent drying of the substrate and to inhibit spreading of the ink into the substrate. The subsequent reheating of the ink in a controlled manner causes the ink to penetrate to a desired extent into the substrate while preventing shrinkage or cockling of the substrate.

Abstract: In the particular embodiment of an ink deaerator described in the specification, an elongated ink path leading to an ink jet head is formed between two permeable membranes. The membranes are backed by air plenums which contain support members to hold the membranes in position. Reduced pressure is applied to the plenums to extract dissolved air from the ink in the ink path. Increased pressure can also be applied to the plenums to eject ink from the ink jet head for purging. Within the ink jet head ink is circulated convectively from the orifice to the deaerating path even when the jet is not jetting ink.

Abstract: In the particulate embodiments described in the specification, a hot melt ink jet system includes a temperature-controlled platen provided with a heater and with a thermoelectric cooler electrically connected to a heat pump, and a temperature control unit for controlling the operation of the heater and the heat pump to maintain a substrate on the platen which receives the ink at a temperature which provides a desired spot size without causing print-through. In certain embodiments, the substrate temperature is from about 20.degree. C. above to about 20.degree. C. below the melting point of the ink and is determined by subtracting half the difference between the jetting temperature and the temperature at which the ink has a viscosity of about 200-300 cp from the latter temperature.

Abstract: In order to detect positions, an optical encoder utilizes the phenomenon that the ratio in intensities of diffracted light beams of different orders change depending on the patterns of aperture ratios in one pitch of a grating on the scale, and that the distance between the positive and the negative diffracted light beam of the same order vary depending on the patterns of the grating pitch on the scale, or that the light spots of the positive and the negative diffracted light beams of the same order move (rotate) depending on the patterns of the grating line direction. Therefore, this optical encoder is free from the adverse influence of fluctuations in the amount of coherent light illuminated from the light source to thereby enable precise positional detection.

Abstract: In the particular embodiments of the invention described in the specification, the pressure chamber for an ink jet system is coated with a smooth, conforming layer of a coating material, such as a xylylene polymer material, which is wettable by the ink used with the system to eliminate nucleation sites in the surfaces forming the walls of the chamber and thereby inhibit formation of bubbles from dissolved air contained in ink within the chamber when the ink is subjected to reduced pressure during operation of the ink jet system.