Abstract: A bipolar ink jet driver circuit includes a plurality of individual driver cells having a common collector and a resistive heater element. A common collector obviates the need for any isolation between adjacent driver cells. The driver cells each include two bipolar transistors configured as a Darlington pair, which drive an associated resistive heater element. The cells are grouped together to form individual driver circuits each having a control line for enabling each driver circuit. The cells within each driver circuit are individually addressable via address lines which are coupled to each of the driver elements. The resistive heater elements are actuated by enabling a driver circuit and addressing a driver cell within the enabled driver circuit.

Abstract: This invention provides an apparatus and method of fabrication thereof for an inkjet printhead with an improved ink flow path between an ink reservoir and vaporization chambers in an inkjet printhead. In the preferred embodiment, a barrier layer containing ink channels and vaporization chambers is located between a rectangular substrate and a nozzle member containing an array of orifices. The substrate contains two linear arrays of heater elements, and each orifice in the nozzle member is associated with a vaporization chamber and heater element. The ink channels in the barrier layer have ink entrances generally running along two opposite edges of the substrate so that ink flowing around the edges of the substrate gain access to the ink channels and to the vaporization chambers. The apparatus is fabricated without using ion implant technology.

Abstract: A bipolar ink jet driver circuit includes a plurality of individual driver cells having a common collector and a resistive heater element. A common collector obviates the need for any isolation between adjacent driver cells. The driver cells each include two bipolar transistors configured as a Darlington pair, which drive an associated resistive heater element. The cells are grouped together to form individual driver circuits each having a control line for enabling each driver circuit. The cells within each driver circuit are individually addressable via address lines which are coupled to each of the driver elements. The resistive heater elements are actuated by enabling a driver circuit and addressing a driver cell within the enabled driver circuit.

Abstract: The interconnections for transmitting print commands from a printer to a printhead are reduced by the use of on-printhead circuitry. In a basic embodiment, the printhead driver circuitry includes a matrix of drivers controlled by gates, power and control interconnections. Interconnections are reduced by enabling rows and columns of drivers with the power and control interconnections. A multiplexer may also be added to further reduce control interconnections. In an advanced embodiment, the printhead driver circuitry includes a register for converting a serial stream of print enable signals from the printer into a format for applying such signals concurrently to switching devices for one or more heater resistors. An address generator on the printhead generates address signals in response to an address generating signal from the printer. The printer provides constant power to the printhead so that energizing of the heater resistors is a function of the address and print enable signals and not of the power.

Abstract: An integrated circuit for use in the printhead of an ink jet printer includes an array circuit for heating an ink reservoir to produce a pattern of ink jets, the array circuit including a plurality of resistor cells arranged into rows and columns. A corresponding number of row and column lines are coupled to the integrated circuit array for selecting and energizing the resistor cells according to the desired printing pattern. An identification circuit integrated into the same substrate as the array circuit includes one or more programmable paths, the programmable paths corresponding and coupled to each row line. The programmable paths each include the serial combination of a programmable fuse and an active device. The opposite end of the programmable paths are coupled together at a common node, which in turn is coupled to an output circuit for providing a single output signal in response to a polling of the row lines.

Abstract: A system for generating an analog regulating voltage to be supplied to one or more circuit elements on an integrated circuit. The circuit elements have operational characteristics that are voltage dependent and the analog regulating voltage having the a property of changing with temperature, power supply voltage, and manufacturing process variations so as to substantially eliminate the effects of such variations on the operational characteristics of the circuit elements.

Abstract: An improved thermal inkjet printhead having MOSFET drive transistors incorporated therein. The gate of each MOSFET transistor is formed by applying a layer of silicon dioxide onto a silicon substrate, applying a layer of silicon nitride onto the silicon dioxide, and applying a layer of polycrystalline silicon onto the silicon nitride. Portions of the substrate surrounding the gate are oxidized, forming field oxide regions. Drain and source regions are then conventionally formed, followed by the application of a protective dielectric layer onto the field oxide, drain, source, and gate. A resistive layer is deposited on the dielectric layer and directly connected to the source, drain, and gate. A conductive layer is deposited on a portion of the resistive layer, ultimately forming both covered and uncovered regions thereof. The uncovered region functions as a heating resistor, and the covered regions function as electrical contacts to the transistor and resistor.