Texas Instruments Corporation

Lexmark International, Inc.

Ronald E Garnett

Mitchell R Rowlette

Walter H Bailey

Youn H Ting

Mark Eric Miller

David Allen Crutchfield

James Ray Bailey

Curt Paul Breswick

Timothy Lee Anderson

James Alan Ward

Mark A Eifler

Bob Thai Pham

Error diffusion is performed upon input image data. In one aspect, multiple error diffusion processing elements perform error diffusion on a selected pixel in parallel. In another aspect, the error diffusion logic is integrally formed with a fast local memory in the same electronic device, such as an ASIC. The error data produced by the error diffusion logic for a pixel is buffered in the fast local memory until it is to be used by the error diffusion logic on other pixels. In still another aspect, a first-in-first-out (FIFO) buffer regulates or buffers the color image data between the output of a color conversion system, such as a colorant lookup table, and the input an error diffusion processing element. In yet another aspect, the error diffusion logic has tagging logic that produces and stores an indicator, either in the output data stream itself or in a separate area, to indicate whether a raster contains printable data.

Systems and methods for error diffusion

In a receiver circuit module (,) having a microcontroller (U,), an output line (FILTER_LED) connectable to a source circuit module (,) is also used as an input. A switch (SW,) disposed in the source circuit module is closed to change the wave form which is read by the microcontroller as an input signal to drive a 5V signal to the gate of a solid state switch (Q,) turning it on to thereby energize an output device in the source circuit module via the same output line (FILTER_LED). By means of the dual function of the output line the control can notify a user of an HVAC system, for example, of system problems with a blinking light and/or an audible alarm as well as serving to notify the user at a remote location that selected maintenance is due, such as a need to change filters without additional control lines. The source circuit module can be mounted near the thermostat of the HVAC system or on the central heating and cooling unit.

Method and apparatus using phases for communication in thermostat circuit

A low cost, microprocessor (U,) based motor controller (,) for driving a half-wave, multiple speed, reversible, DC brushless motor (,) directly from standard AC 50/60 Hz power. A large number of different speed and rotation direction combinations may be chosen before or after the motor is installed using configuration resistors (R,, R,). SIDACs (TS,, TS,) each serially connected to a diode (D,, D,) are connected across respective coils (COIL,, COIL,) to clamp the flyback energy in the windings to a few volts when triggered and allow Vemf to float when not triggered. The control adjusts the relative phase timing of commutation during start-up and during running to enhance efficiency. Locked rotor protection is provided by limiting start-up time to a selected period which is followed by a selected cool-off time.

DC brushless motor controller apparatus and method

An electric control is shown adapted for use with gas furnaces which controls fan motors, ignition controls and a gas valve based on inputs from a room thermostat, limit switches, a flame probe, a flame roll-out probe, and a condensate sensor. A roll-out detection circuit utilizing flame rectification includes a multidirectional roll-out probe 16 coupled to a microcontroller (U2) through an inverter (U3) to provide both fault both protection and fault identification. A condensate sensor (20) in the form of a conductive condensate sensor member is also coupled to the microcontroller (U2) through an inverter (U3) to detect the presence of condensate build-up.

Combined fan and ignition control with selected condition sensing

A gas fired furnace system (10) has a controller (14) controlling the supply of gas through a gas valve (12) and air for combustion by means of an induced air draft fan (28), ignition of the gas by means of ignitor (22), the delivery of heated air from a heat exchanger (20) by means of an air blower (34) in response to signals from a thermostat (42). A selected constant flow of air for combustion is provided by controlling the speed of the motor driving the induced motor fan (28) despite changes which may occur in back pressure. Induced draft fan motor parameters proportional to motor torque and motor speed are read on an ongoing basis and inputted to controller (14) which computes a desired voltage and compares that with referenced data stored in the controller memory and makes corrections to the speed of the induced draft fan motor to maintain the constant air flow. The motor speed and motor torque are also monitored to ensure that they are within selected limits indicative of safe operation and responsive to this input energization of a relay (KM1) is controlled to deenergize the gas valve and ignition.

Method for controlling an induced draft fan for use with gas furnaces

Induced draft fan control for use with gas furnaces

A temperature control system is shown in which a thermostat circuit is combined with a power supply to produce a higher anticipator current for a W1 signal while reducing power consumption and heat generation of the circuit. A first relay power signal is provided by an unbalanced bridge rectifier (D1, D2, D3, D4, D7, D8) while current drawn through the anticipator resistor (AR1) by means of an additional bridge rectifier circuit (D7, D8, D9, D10) is merged with the first relay power signal. In a second embodiment, an unbalanced bridge rectifier (D1, D4, D7, D2, D3, D8) has an output connected to a first stage relay power signal line as well as to second and third relay power signal lines. A second stage of the power supply includes a first additional bridge rectifier (D5, D6, D7, D8) connected to the second relay power signal line that drives current through the W1 anticipator while in a third stage of the power supply a second additional rectifier (D20, D21, D7, D8) is connected to the third relay power signal line and draws current through the W2 anticipator. Each stage of power adds more capacitance (C12, C11, C10) as the power requirements increase.

Growing community of inventors

Lexington, KY, United States of America

Ronald E Garnett