Abstract: A variable attenuation device includes a resistive array having two or more input nodes, two or more output nodes, and two or more resistive devices for coupling the input nodes and the output nodes. A first switch has an input terminal and two or more selectable output terminals, such that the input terminal is configured to receive an input signal and the two or more selectable output terminals are coupled to the two or more input nodes of the resistive array. A second switch has two or more selectable input terminals and an output terminal, such that the output terminal is configured to provide an attenuated output signal and the two or more selectable input terminals are coupled to the two or more output nodes of the resistive array.

Abstract: An embodiment of a media movement apparatus is used to detect an edge of a unit of media in a media path in an inkjet printer using an optical sensor. When the inkjet printer is operating in a mode in which units of media are continuously moved into the media path, a mechanical sensor will not reliably allow detection of the leading edge of a unit of media. Determining the location of the leading edge of the unit of media is done to correctly place an image on the unit of the media. After ejecting the previous unit of the media into an output tray, the current unit of the media is moved backward in the media path while measuring the output of an optical sensor. If the edge is detected while moving backward, the current unit of the media is moved to the input side of a print zone. If the edge is not detected and the optical sensor indicates the presence of media, a media jam is indicated.

Abstract: Use of a shrouding gas to combine with and protect a turbulent gas jet issuing from an orifice enables control of a gas jet stream composition downstream from the orifice. The natural aspiration rate of the gas jet is used to determine the flowrate of shrouding gas which is introduced around the gas jet in a soft gas cushion which does not disrupt the flow pattern of the gas jet but instead is entrained into the jet stream to the exclusion of ambient gases in the atmosphere. Preferably shrouding gas is replaced at least at the rate at which it is entrained. Apparatus for this process uses a porous shroud, preferably of metal foam, through which shrouding gas flows evenly around the gas jet as it issues from a nozzle orifice. Provision for tangential entry of shrouding gas into a manifold which feeds the porous shroud prevents the shrouding gas from impinging upon the porous shroud and causing uneven flow around the gas jet.

Abstract: Use of a shrouding gas to combine with and protect a turbulent gas jet issuing from an orifice enables control of a gas jet stream composition downstream from the orifice. The natural aspiration rate of the gas jet is used to determine the flowrate of shrouding gas which is introduced around the gas jet in a soft gas cushion which does not disrupt the flow pattern of the gas jet but instead is entrained into the jet stream to the exclusion of ambient gases in the atmosphere. Preferably shrouding gas is replaced at least at the rate at which it is entrained. Apparatus for this process uses a porous shroud, preferably of metal foam, through which shrouding gas flows evenly around the gas jet as it issues from a nozzle orifice. Provision for tangential entry of shrouding gas into a manifold which feeds the porous shroud prevents the shrouding gas from impinging upon the porous shroud and causing uneven flow around the gas jet.