Abstract: In the embodiments of the simplified ink jet head described in the specification, a carbon body is formed with ink passages, such as internal passages extending through a carbon plate, pressure chambers on one side of a carbon plate, flow-through passages on the other side of the same plate and ink supply passages, and a piezoelectric plate is affixed to the pressure chamber side of the carbon plate by a thin layer of epoxy adhesive. The piezoelectric plate may have a conductive coating on one side which is photo-etched to produce an electrode pattern corresponding to the pattern of the pressure chambers in the carbon plate. An orifice plate may have specially profiled orifice openings to assure axial projection of drops and may be affixed by a thin layer of epoxy adhesive to a carbon plate having orifice passages supplying ink from the pressure chambers to the orifices.

Abstract: In the embodiments of the simplified ink jet head described in the specification, a carbon body is formed with ink passages, such as internal passages extending through a carbon plate, pressure chambers on one side of a carbon plate, flowthrough passages on the other side of the same plate and ink supply passages, and a piezoelectric plate is affixed to the pressure chamber side of the carbon plate by a thin layer of epoxy adhesive. In one alternative embodiment, an ink jet head assembly contains two separate carbon pressure chamber plates, a carbon manifold plate and a carbon collar to retain the carbon plates in an assembly.

Abstract: In the embodiments of the simplified ink jet head described in the specification, a carbon body is formed with ink passages, such as internal passages extending through a carbon plate, pressure chambers on one side of a carbon plate, flowthrough passages on the other side of the same plate and ink supply passages, and a piezoelectric plate is affixed to the pressure chamber side of the carbon plate by a thin layer of epoxy adhesive. The piezoelectric plate may have a conductive coating on one side which is photoetched to produce an electrode pattern corresponding to the pattern of the pressure chambers in the carbon plate. An orifice plate may have specially profiled orifice openings to assure axial projection of drops and may be affixed by a thin layer of epoxy adhesive to a carbon plate having orifice passages supplying ink from the pressure chambers to the orifices.

Abstract: In the simplified ink jet head described in the specification, a tubular member made of air-permeable, ink-permeable material which is closed at one end and connected at the other end to a source of subatmospheric pressure is inserted into an ink passage in the ink jet head to extract dissolved air through the material of the tubular member from a surrounding body of ink in the ink passage.

Abstract: In the embodiments of the simplified ink jet head described in the specification an orifice plate has specially profiled orifice openings to assure axial projection of drops when ink is supplied from an asymmetric ink path leading to the orifice. For this purpose the orifice includes cylindrical ink inlet and outlet portions with the ink outlet portion having a smaller diameter and a shorter length than the inlet portion and a tapered conical portion joining the ink inlet portion and the ink outlet portion. Preferably, the diameter of the inlet portion is no more than about twice the diameter of the outlet portion.

Abstract: In the embodiments described in the specification, a ceramic piezoelectric plate is polarized by compressing the plate between electrode plates with intervening slightly conductive rubber sheets or by applying electric charge from a corona discharge device to one surface of the plate while the opposite surface is grounded until the applied charge is sufficient to create a breakdown.

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 particular embodiments of the invention described in the specification, a transparency includes a transparent substrate made of a polyester material, an ink pattern disposed on one surface of the transparent sheet in the form of three-dimensional ink spots having curved surfaces and a transparent layer convering the ink spots which has an index of refraction approximately the same as that of the ink spots. The transparent layer is applied to the substrate and the ink spots in the form of a liquid coating which wets the surfaces of the substrate and ink spots and spreads over them to produce a transparent layer having a maximum deviation of about 20 degrees from a plane parallel to the substrate.

Abstract: A transparency includes a transparent substrate such as a polyester material, an ink pattern disposed on one surface of the transparent sheet in the form of three-dimensional ink spots having curved surfaces and a transparent layer covering the ink spots which has an index of refraction approximately the same as that of the ink spots. The transparent layer is applied to the substrate and the ink spots in the form of a liquid coating which wets the surfaces of the substrate and ink spots and spreads over them to produce a transparent layer having a maximum deviation of about 20 degrees from a plane parallel to the substrate.